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Three-Figure Bearings for Sengkang Families: Start at North and Turn Clockwise

Secondary students working together during a small-group tuition lesson

eduKateSengkang · Family learning

Find your next learning step

Choose the route closest to your question. Read one worked example, try a fresh case and use the explanation to check the decision behind your answer.

Route 1 · Chapters 1–4

Start at the right point

Find the reference vertex, north and the direction of turn.

Route 2 · Chapters 5–9

Draw and reverse

Construct rays, check quadrants and distinguish inside angles.

Route 3 · Chapters 10–15

Solve a route

Use scale, components and intersections.

Route 4 · Chapters 16–20

Check the model

Distinguish displacement and direction and try a drawing task.

Route 5 · Chapters 21–24

Calculate and explain

Work through route questions and a paper map challenge.

Full chapter index · Start the diagnostic · Continue at the learning hub

On a fictional map, a shelter is on a bearing of 065° from a gate. That tells you where to face from the gate. It does not tell you how far to go, which path to take, or the direction from the shelter back to the gate. This guide teaches how to mark the starting point, draw north there, turn clockwise, and check the result. Use the examples on paper; they are geometry practice, not local navigation directions.

Similar triangles for families · Secondary 3 applications of trigonometry

Choose a chapter

Start at the right point · Chapters 1–4
  1. Name the point where the measurement begins
  2. Use a clockwise turn measured from north
  3. Write the three figures after solving the angle
  4. Distinguish a bearing from a distance
Draw and reverse · Chapters 5–9
  1. Translate directions stated from another compass line
  2. Use the correct protractor scale
  3. Draw a reflex bearing with a smaller angle
  4. Find the reverse bearing with a half-turn
  5. Separate a bearing from an interior angle
Solve a route · Chapters 10–15
  1. Find a turn at an intermediate point
  2. Check that north is parallel at all points on the sketch
  3. Convert a drawing length and keep the angle
  4. Decompose a bearing into east and north components
  5. Find a bearing from components
  6. Find a destination where two rays intersect
Check the model · Chapters 16–20
  1. Solve a two-leg route by tracking net movement
  2. Avoid using school diagrams as real-world navigation instructions
  3. Diagnose the first error before redoing the work
  4. Independent practice: draw and reverse
  5. Explained answers: draw and reverse
Calculate and explain · Chapters 21–24
  1. Independent practice: calculate and test the model
  2. Explained answers: calculate and test the model
  3. Try a brief paper map challenge
  4. Family questions and next steps

CHAPTER 1 OF 24 · Start at the right point

1. Name the point where the measurement begins

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“The bearing of B from A” means stand at A and look toward B. The word from names the starting point. Write “A → B” beside the problem before drawing anything. In “the bearing of A from B,” the starting point is B instead, so the turn is measured at B. The letter that appears first in English is not necessarily the first point in the direction of travel.

Place two slips on a table and name them Gate and Shelter. Ask one learner to stand at Gate and point to Shelter, then move to Shelter and point to Gate. The two hands point along the same connecting line but in opposite directions. That experience helps separate the angle’s vertex from the destination. Neither bearing is a property of the destination alone.

Try three phrases: “from the bench to the sign,” “of the sign from the bench,” and “of the bench from the sign.” The first two have the same direction. The third reverses it. If someone chooses a starting point by following the order in which nouns appear, have them underline from and convert the phrase to an arrow. Once the point is correct, draw the north arrow there. An accurate angle measured at the wrong point can still give the wrong answer.

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CHAPTER 2 OF 24 · Start at the right point

2. Use a clockwise turn measured from north

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Start on the north ray, then turn toward east, south, west and back to north. East corresponds to 090°, south to 180° and west to 270°. Due north is 000° when bearings are represented in the interval from 0° up to but excluding 360°. A complete clockwise turn also points north; on this scale write the starting equivalent, 000°.

A bearing of 070° lies between north and east. A bearing of 290° lies between west and north. If you make a 70° turn to the left from north, you also face between west and north, but the clockwise bearing is 290°. Keep the direction of the turn separate from the size of the smaller angle drawn at the point.

Try this without a protractor: draw the cardinal directions and ask where 110°, 205° and 330° belong. The first is between east and south, the second between south and west, and the third between west and north. Place each approximately before measuring it. A quadrant check is fast and catches many errors where a learner reads the wrong scale on a protractor. It does not prove the precise angle, so use the given numbers or a measuring instrument to complete the answer.

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CHAPTER 3 OF 24 · Start at the right point

3. Write the three figures after solving the angle

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A clockwise turn of 8° is written 008° as a three-figure bearing. A turn of 42° is 042°. A turn of 137° already has three figures. The leading zeroes do not change the size of the turn. They help readers recognise that a number is intended as a bearing when the context calls for three figures.

Distinguish formatting from calculation. A learner may find the correct numerical angle of 57° but write a two-figure bearing. The repair is 057°, not 570° and not 005°. On the other hand, writing 057° instead of 303° cannot repair a turn measured anticlockwise. Check the ray and the direction before adding zeroes. A correctly formatted answer is still wrong if its destination is on the wrong side of north.

If the problem gives a decimal or asks for a nearest-degree answer, follow the stated precision. For example, a calculated turn of 64.6° is 065° to the nearest degree. A result of 359.7° rounds to a full turn, equivalent to 000° in the convention used here. If an instrument reports 359.7° and the task asks for the instrument reading, preserve the decimal. Do not lose given precision just because familiar school examples use whole degrees.

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CHAPTER 4 OF 24 · Start at the right point

4. Distinguish a bearing from a distance

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On a fictional map a sign is on a bearing of 040° from a post. Draw a ray in that direction. The sign could lie one metre along the ray or ten metres along it; both positions have the same bearing. A distance or another geometric constraint is needed to locate one point. A ray represents all possible locations along that direction, except the starting point itself.

If the sign is 6 metres away and the map scale is 1 cm for 2 m, measure 3 cm along the ray. The length comes from the scale and the angle from the bearing. Mark the point only after doing both jobs. A second sign 8 metres away on the same bearing would lie farther along the ray, without requiring another turn.

Ask what is missing in each description. “The shelter is 5 metres from the post” gives a distance and allows a whole circle of possible positions. “The shelter is on a bearing of 040° from the post” gives a ray. Together they identify a position on that ray. This distinction matters in word problems that give two bearings from different landmarks rather than a distance. There the second ray may supply the missing constraint through intersection.

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CHAPTER 5 OF 24 · Draw and reverse

5. Translate directions stated from another compass line

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“A direction 20° east of north” begins at north and moves toward east, so it is bearing 020°. “20° west of north” moves from north toward west, anticlockwise. The clockwise bearing is 360° − 20° = 340°. The difference between the two rays is visible even though both descriptions contain the same number.

Now start at south. “30° east of south” points between east and south. The clockwise bearing is 180° − 30° = 150°. “30° west of south” points between south and west and gives 180° + 30° = 210°. Draw the compass cross before deciding which operation fits. A phrase such as east of south tells you a starting reference and a side; it does not automatically mean add to the bearing for south.

Try “15° north of west.” Start at west, bearing 270°, then move toward north by another 15° clockwise. The answer is 285°. Compare “15° west of north,” which gives 345°. These are different because the first is close to west and the second is close to north. Invite the learner to describe their final ray as closer to one cardinal direction than another. That check makes the wording meaningful rather than a set of memorised plus and minus rules.

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CHAPTER 6 OF 24 · Draw and reverse

6. Use the correct protractor scale

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Place the centre of the protractor over the starting point. Align the zero reference with the north ray. Read the scale that increases in the intended direction. A half-circle protractor often prints 50° and 130° along the same line because it measures from opposite reference edges. Only one is the turn from the chosen zero. Check whether your ray should be closer to north or south before trusting the printed number.

Suppose you need 055°. Draw north, mark a point 55° clockwise from it and connect that mark to the start. The ray lies between north and east and closer to east because 55° exceeds 45°. If it falls between east and south, the selected scale or orientation was wrong. If it lies west of north, the turn went the wrong way. Each visual mistake suggests a different repair.

When a drawing is too small to place the protractor, extend the ray lightly without changing its direction. Keep the centre at the original vertex. If the question says the diagram is not to scale, use stated angles and angle facts rather than measuring the picture. A sketch may be enough to show where a turn lies, but measuring an intentionally rough sketch cannot supply an exact missing angle.

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CHAPTER 7 OF 24 · Draw and reverse

7. Draw a reflex bearing with a smaller angle

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To draw bearing 315°, imagine turning clockwise through 270° to west, then another 45° toward north. With a semicircular protractor, it can be easier to draw a 45° angle anticlockwise from north. Mark the bearing itself as 315°. The smaller construction angle and the clockwise bearing are different readings for the same ray.

For 220°, the ray is 40° west of south. Draw south, then mark 40° toward west. The full bearing is 180° + 40°. A learner who writes 040° after constructing the ray has recorded the small construction angle rather than the requested clockwise turn from north. Label both angles in a practice sketch to keep them apart.

Consider 275°. It is only 5° beyond west in a clockwise turn, so the ray should sit just north of west. It is 85° anticlockwise from north. Either construction works if the final ray is the same. Ask the learner which construction is easier to measure accurately on their paper. A small angle may fit the diagram well, while a ray almost parallel to an axis can make the protractor marks hard to read. Use the quadrant and closeness to west as checks.

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CHAPTER 8 OF 24 · Draw and reverse

8. Find the reverse bearing with a half-turn

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If B is on a bearing of 064° from A, the bearing of A from B is 244°. The new ray points in the opposite direction, which is a turn of 180° relative to the first. Draw parallel north rays at both locations. The line of travel points northeast from A and southwest from B. That matches the difference of a half-turn.

For a forward bearing of 246°, adding 180° gives 426°, which is beyond one full turn. Subtract 360° to write the equivalent 066°. You can also subtract 180° directly from a bearing of at least 180°. For a forward bearing below 180°, add 180°. At exactly 180°, the reverse is 000°. The rule keeps the answer in the chosen interval.

Try using the reverse rule twice. Starting with 301°, reverse to 121° and reverse again to 301°. This check exposes a result such as 059°, which might come from subtracting from 360° instead of adding a half-turn. Subtracting from 360° reflects many rays across the north–south line; it does not generally point back to the starting location. For a school sketch, the north lines must be parallel for this local geometry rule. Do not extend it uncritically to navigation over a large curved surface.

There are two quick checks for a reverse bearing. The north or south component must reverse, and the east or west component must reverse. A ray on 110° is east and south. The return must be west and north, and 290° fits both tests. The same check works on the axes: reverse of 090° is due west, so it cannot still be due east even though both directions are horizontal. Check one more case at a boundary. A forward bearing of 179° points just east of south. Its reverse, 359°, points just west of north. Adding a half-turn preserves the small offset from the north–south line while reversing the side of that line.

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CHAPTER 9 OF 24 · Draw and reverse

9. Separate a bearing from an interior angle

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Two paths leave A on bearings 040° and 110°. The smaller angle between them is 110° − 40° = 70°. That 70° is a turn from one path to the other, not the bearing of either path. To call it a bearing you would need a ray 70° clockwise from north. Draw north and both paths so that each arc has a clear start.

Now use bearings 335° and 025°. Subtracting the smaller from the larger gives 310°. That is one of the two angles around A. The smaller angle crosses north and equals 360° − 310° = 50°. You can find it directly as 25° before reaching north plus 25° after passing north. Choose the angle that the question requests. If it asks for the clockwise turn from 025° to 335°, 310° is appropriate.

Mark the centre for an angle named by three letters. For angle ABC, B is the vertex and the arms go toward A and C. The bearing of C from B also starts at B, but its other arm is north rather than BA. A shared vertex does not make the two angles interchangeable. Write the starting ray for each angle before deciding whether to add, subtract or use a full turn.

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CHAPTER 10 OF 24 · Solve a route

10. Find a turn at an intermediate point

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Suppose a route goes from A to B on bearing 070°, then from B to C on bearing 140°. At B, the ray back toward A is on bearing 250°. The smaller angle ABC is between 250° and 140°, so it is 110°. Subtracting 70° from 140° gives 70° instead. That 70° describes the change between the forward headings, which is a different angle.

Use a toy arrow to make the difference visible. Move it from A to B without rotating it. It is still facing 070° when it arrives. Turning it to the new heading 140° changes its facing direction by 70° clockwise. Now put one finger on B and point back toward A. That back ray goes opposite to the incoming heading, so the inside angle between BA and BC is 110°. The two measures are supplementary in this example.

Ask the learner to label what a question means by “turn at B.” In everyday directions it could mean rotate from the current facing direction. In a geometry question it could refer to the interior angle with vertex B. If the wording or diagram gives angle ABC, use the ray BA. If a traveller is asked how far to turn from the direction of motion, use the current forward heading. Being precise here prevents a correct subtraction from answering the wrong question.

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CHAPTER 11 OF 24 · Solve a route

11. Check that north is parallel at all points on the sketch

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For small flat school diagrams, draw each north ray pointing in the same direction. Some problems show north at only one location. Copy that orientation at the next point rather than drawing a new ray pointing toward the top edge by habit. A map can be rotated on the table. If its north arrow tilts left on the page, use that arrow as the reference and draw the others parallel to it.

Imagine a drawn ray that looks horizontal on the page. If north points to the left on this particular drawing, a leftward route is due north and a rightward route is due south. The paper edge is not part of the definition. Check the stated north arrow before interpreting the sketch. If there is no direction key and the problem does not state that page-up means north, do not infer an exact bearing from appearance alone.

When north rays are parallel, the route segment crossing them can be used with corresponding or alternate angle relationships. A half-turn provides a quicker way to get a reverse bearing, but drawing both rays explains why it works. Ask the learner to show which lines are parallel and where an interior angle lies. That explanation transfers to more complex diagrams better than memorising a rule detached from its assumptions.

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CHAPTER 12 OF 24 · Solve a route

12. Convert a drawing length and keep the angle

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A scale of 1 : 2,000 means one unit on the drawing represents 2,000 of the same units on the ground. One centimetre represents 2,000 centimetres, or 20 metres. A line 4.5 cm long therefore represents 90 metres. If the drawn line has bearing 120° from A, its distance and direction can be reported separately as 90 m on a bearing of 120° from A.

If a drawing is enlarged uniformly, lengths on the new copy change but angles are preserved. The printed scale ratio may no longer be right unless it is updated. If the image is stretched in only one direction, even the angle can change. Use the original or a correctly scaled diagram when a task expects measurement rather than inference from stated values.

Try planning a model: draw two rays from A, one on 060° and one on 150°, each ending 3 cm away. With the given scale both endpoints are 60 m from A. The interior angle between rays is 90°. If a learner thinks both destinations are the same because their distances match, ask them to point along each ray. Distance and direction are independent pieces of information. A scale tells you how far the point is, not which way to look.

Another way to recover a scale is to use a known pair of lengths. If a baseline drawn as 7 cm represents 140 m, the working scale is 1 cm to 20 m. A route drawn at 085° and measuring 3.6 cm represents 72 m. Suppose that baseline is later measured as only 3.5 cm on a smaller copy. The working scale for that copy is 1 cm to 40 m, and a uniformly reduced route should measure 1.8 cm. It still represents 72 m. This provides a check on whether the reduction is consistent. If the copy gives different reduction factors along two directions, do not trust the measured bearing or one ratio for every route.

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CHAPTER 13 OF 24 · Solve a route

13. Decompose a bearing into east and north components

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Use the idea that east and north can be measured separately. A path of length 10 m on bearing 030° lies east and north of the start. Draw the horizontal and vertical legs of a right triangle. The 30° angle is from the north leg to the path. The north component is adjacent to that angle, so it is 10 cos 30° = 5√3 m. The east component is opposite, so it is 10 sin 30° = 5 m.

A learner might associate cosine with the horizontal leg because many coordinate problems measure angles from a horizontal axis. Here the bearing starts at north. The adjacent leg is determined by the diagram, not by a rule about the horizontal direction. Check that the north component is longer than the east component, since the ray is closer to north than east.

For a route on bearing 150°, the ray lies east and south. It is 30° east of south. An east component of 5 m and a south component of 5√3 m describe the same triangle with a different vertical direction. In signed coordinates with north positive, the north component is negative. A rough quadrant sketch helps a learner detect a sign error before working with trigonometric values.

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CHAPTER 14 OF 24 · Solve a route

14. Find a bearing from components

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A point is 6 m east and 8 m north of A. From the north ray, the angle to the route satisfies tan θ = 6/8. The inverse tangent gives about 36.87°, so the bearing is 037° to the nearest degree. The distance is √(6² + 8²) = 10 m. The tangent gives an angle; the square-root calculation gives a length. Neither answer replaces the other.

Now put the point 6 m west and 8 m north. The same acute angle, about 36.87°, appears on the west side of north. The clockwise bearing is 360° − 36.87°, about 323.13°, or 323° to the nearest degree. Writing 037° would place the point on the east side. Find the acute reference angle from the leg lengths, then convert to the correct quadrant.

Try a point 6 m east and 8 m south. The reference angle from south toward east is again about 36.87°. The bearing is about 143.13°, or 143°. Direct substitution into a calculator without a quadrant check can hide the difference. If one component is zero, use the cardinal bearing directly rather than dividing by zero. If both are zero, the destination coincides with the start and the direction is undefined.

On an exact grid you can sometimes avoid decimal approximations. If east and north components are both 4 m, the right triangle has equal legs and the acute reference angle is 45°. If the destination lies southwest instead, the equal south and west legs place it on 225°. A learner who reports 045° has correctly noticed the equal legs but lost the sign information. Record the quadrant and exact angle as separate facts before combining them. The same principle works for a 30°–60° right triangle: identify which leg is longer, and identify whether it lies along the east–west or north–south direction. Both choices are needed to name the correct bearing.

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CHAPTER 15 OF 24 · Solve a route

15. Find a destination where two rays intersect

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Place A at the origin of a squared-paper grid and B four squares east. Point C is on bearing 045° from A and bearing 315° from B. Draw the ray from A heading northeast and the ray from B heading northwest. They meet two squares east and two squares north of A. Both rays describe C, so their crossing picks out the point.

The result is not the midpoint of AB, which lies two squares east but has no northward displacement. The equal 45° reference angles make the crossing sit above the midpoint, not on it. Checking both bearings avoids choosing a location just because it looks central. C is at a distance of 2√2 grid units from A under the Euclidean model.

If both rays point due north from distinct east–west locations, they are parallel and never meet. If two rays lie along the same line and overlap, their overlap may contain many possible locations. Sometimes the infinite lines intersect behind one starting point, which does not count because that direction is outside its ray. In an exercise with drawing inaccuracies, a near-intersection is a reason to inspect scale and angles. With exact information, distinguish a unique crossing, no crossing and many possible points.

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CHAPTER 16 OF 24 · Check the model

16. Solve a two-leg route by tracking net movement

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A fictional route begins at A, goes 12 m due east to B and then 5 m due north to C. The first leg has bearing 090° and the second 000°. From A to C the displacement is 12 m east and 5 m north. Its distance is 13 m by Pythagoras. Its bearing is arctan(12/5), about 67.38°, so 067° to the nearest degree. The path actually walked is 17 m, not 13 m.

The clockwise heading change from due east to due north is 270°, while the smaller turn a traveller can make is 90° anticlockwise. Both descriptions produce the new heading. The interior angle ABC is 90° between the westward ray BA and northward ray BC. Different questions ask for different properties, even when the same number 90° appears more than once.

Extend the route by adding 12 m west from C to D. The net eastward movement cancels, leaving D 5 m north of A. The bearing of D from A is 000°. A longer total walking distance does not imply that the endpoint is farther away. Draw an arrow for each leg, then a distinct arrow for the direct start-to-end displacement. That makes the correct reference point visible when the wording switches between travel and position.

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CHAPTER 17 OF 24 · Check the model

17. Avoid using school diagrams as real-world navigation instructions

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The north reference in a school problem is the one printed or specified. Real maps or compasses can use different north references, and a numerical direction does not say whether a route is passable. A line between two points can cross a wall or a canal. A safe actual route may require turns that are not on the direct bearing. This guide’s invented examples describe geometry on a flat sketch and do not describe routes around Sengkang.

Even within a sketch, drawing accuracy has limits. Two learners measuring the same short printed line may read 053° and 055°. If a labelled value of 054° is given, use it for exact deduction. If the task asks for a measurement, record a defensible reading to the specified precision. A narrow estimate is better justified by a longer, clearly drawn ray than by guessing several decimal places from a small picture.

Ask what source supports each part of an answer: a stated bearing, a measured drawing, an exact calculation or a contextual assumption. That habit prevents a learner from treating every diagram mark as measured truth. A sketch can guide reasoning without serving as evidence of distance, accessibility or direction outside the problem.

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CHAPTER 18 OF 24 · Check the model

18. Diagnose the first error before redoing the work

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A learner is asked for the bearing of C from B and places the protractor at C. Fix the starting point before checking the arithmetic. Another learner starts at B but draws north along BA. Fix the reference ray before checking the clockwise turn. A third starts at the right point and uses north but takes the smaller angle on the west side, writing 050° instead of 310°. In that case the ray is correct and the reported bearing needs repair.

A separate learner writes “The bearing is 110 metres.” The number may come from a calculation about distance, but the unit cannot belong to a bearing. Identify the question and trace the number to its source. Then decide whether you need a ray direction in degrees or a length with a measurement unit. The diagnostic table gives an order for these checks.

Use a worked sketch with one deliberate mistake. Have the learner find it and state what still works. For example, a correct scale length with an incorrect turn may put the destination at the correct distance but wrong position. Naming the first wrong decision makes the repair smaller and easier to remember. It also shows which skills are already secure.

Try a mixed diagnostic with this sentence: “The destination lies northwest of A, 4 cm away on the drawing, on bearing 045°.” The stated quadrant and numerical bearing disagree. The scale length alone cannot decide between them. The two directions 045° and 315° are mirror images across north. If the quadrant is authoritative, 315° could be the intended bearing, provided the reference angle is 45°. If the numerical bearing is authoritative, the correct quadrant is northeast. An editor should flag the contradiction and check the source instead of silently choosing which information to discard. This is especially useful when a map combines a diagram, a caption and a table.

First checkWhat to doTypical correction
Starting pointFind the word fromPut the protractor at the start
ReferenceDraw north thereKeep north lines parallel on the flat sketch
DirectionTurn clockwiseReport 310°, not the small 50° angle to the west
QuantityName angle or lengthGive degrees for bearings and distance units for lengths
Original diagnostic: check the vertex before the arithmetic

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CHAPTER 19 OF 24 · Check the model

19. Independent practice: draw and reverse

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1. A bench is on bearing 038° from a gate. Say where to stand, which ray starts the turn, which direction to rotate and which quadrant contains the bench. Draw a sketch, then find the bearing of the gate from the bench.

2. A marker is 25° west of south from a post. Give the three-figure bearing and its reverse. Compare your answer with 155° and explain which side of south that other value describes.

3. Draw two rays from P at bearings 330° and 020°. Find the smaller angle between them. Then find the clockwise turn from the 020° ray to the 330° ray. Explain why the answers differ.

4. An object is 75 m from A on bearing 125°. The scale is 1 cm for 25 m. Draw a labelled plan. What does each number tell you to do? Which side of east does the object occupy?

5. Route AB has bearing 085° from A. Route BC has bearing 160° from B. Find angle ABC and the clockwise turn from the forward heading AB to the forward heading BC. Draw both arcs so a reader can see which is which.

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CHAPTER 20 OF 24 · Check the model

20. Explained answers: draw and reverse

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1. Stand at the gate, start at north and turn clockwise 38°. The bench lies northeast. The reverse is 038° + 180° = 218°, southwest. Draw a north ray at the bench to check that the reversed arrow does not still point northeast.

2. Start at south and turn 25° toward west: 180° + 25° = 205°. The reverse is 025°. Bearing 155° is 25° east of south; it lies on the other side of the north–south line.

3. The smaller angle runs 30° to north from 330°, then 20° beyond it, for 50°. Clockwise from 020° to 330° is 310°. The smaller 50° arc is anticlockwise from the 020° ray, or clockwise if you start on the 330° ray.

4. From A draw the ray at 125°, which lies south of east by 35°. Use length 75 ÷ 25 = 3 cm. The first number for construction is an angle and the second is a drawing length. They combine to locate the endpoint.

5. At B the ray BA has bearing 265°. The smaller angle between BA and BC is 265° − 160° = 105°. The forward headings are 085° and 160°, so the clockwise change is 75°. Angle ABC uses BA, which is the reverse of the forward heading along AB. The two answers total 180°.

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CHAPTER 21 OF 24 · Calculate and explain

21. Independent practice: calculate and test the model

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1. A destination is 9 m east and 12 m north of A. Find the direct distance and bearing to the nearest degree. Then place a second destination 9 m west and 12 m north of A. Which answer stays the same?

2. A path 14 m long is on bearing 060°. Find the east and north components. Give exact values where possible. Check which leg is longer without using a calculator.

3. A goes 8 m due west to B, then 15 m due south to C. Find the total distance walked, the direct displacement length and the bearing of C from A to the nearest degree. Sketch the quadrant before calculating.

4. On squared paper, place P at (0, 0) and Q at (6, 0), with east to the right and north up. Draw the rays bearing 045° from P and 315° from Q. Find their meeting point. What changes if both rays instead point due north?

5. Two people use different-size printouts of the same map. The second is enlarged uniformly to twice the linear size. Which part of a bearing-and-distance reading survives without changing the printed ratio? Explain why the other part needs a fresh scale check.

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CHAPTER 22 OF 24 · Calculate and explain

22. Explained answers: calculate and test the model

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1. Distance is √(9² + 12²) = 15 m. The acute angle from north has tangent 9/12, giving about 36.87°. The eastern destination has bearing 037° and the western one has bearing 323°. The length remains 15 m because the component magnitudes are the same.

2. East is 14 sin 60° = 7√3 m; north is 14 cos 60° = 7 m. The ray lies closer to east than to north, so its eastward leg should be longer. A swap would contradict that diagram check.

3. Total walking distance is 8 + 15 = 23 m. The direct distance is √(8² + 15²) = 17 m. C is southwest. The acute angle west of south is arctan(8/15), about 28.07°. Add to 180° to get about 208.07°, so write 208°.

4. The diagonal rays rise one unit for each horizontal unit toward each other. They meet at (3, 3), which satisfies both bearings. If both point north, they are distinct parallel rays and there is no meeting point.

5. A uniform enlargement preserves the angle, so the bearing survives. A printed line becomes twice as long, while the ground distance does not change. Using the old ratio directly with the new line would double the inferred ground distance. A graphic scale bar enlarged with the drawing could still be used if it retains the correct real-world label.

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CHAPTER 23 OF 24 · Calculate and explain

23. Try a brief paper map challenge

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Mark three invented locations on squared paper and draw one north arrow. Have the learner choose one starting point and describe another point using a bearing and a scaled distance. Let a second person use the description on a fresh sheet. Compare locations relative to the same starting point and orientation. If they miss the target, check the vertex, north ray, clockwise direction and scale in that order.

Try a reverse challenge next. Give the bearing from a shelter to a gate and ask for the bearing from the gate to the shelter without remeasuring. Let the learner justify the half-turn with parallel north rays. Then rotate the whole sheet. The answer should not change because the map’s reference directions rotate with its marks. A learner who keeps using page-up will notice a change and can repair the reference.

For an extension, choose a two-leg route that finishes due north of its start even though neither leg points due north. A northeast leg followed by a northwest leg with equal east and west components is one possibility. Ask how the components cancel. This moves from rule-following to planning and helps the learner distinguish each heading from the overall direction of travel.

A final home check can separate estimation from deduction. Draw a north arrow and a ray that looks roughly northeast. Ask for an estimated bearing, then ask whether an exact answer is available. If nothing is labelled and no measuring tool is allowed, northeast is a qualitative description, not enough to establish 045°. Draw a grid showing equal east and north displacements, and ask again. That new fact makes 045° an exact deduction. In the first case the shape of the sketch is a clue. In the second case the two equal legs supply mathematical evidence. A learner who can explain the difference is less likely to overstate the precision of a result.

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CHAPTER 24 OF 24 · Calculate and explain

24. Family questions and next steps

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Can a bearing be above 180°? Yes. A direction west of south or west of north can require more than a half-turn clockwise from north. Use a smaller construction angle if that is easier, then report the full clockwise bearing. Do not subtract from 360° unless you know which angle you are subtracting and why.

Does the opposite bearing always use 180°? In the flat local diagrams used here with parallel north references, the opposite direction differs by a half-turn. Keep the result within a single turn. When the given bearing is 180°, write the reverse as 000°. If a problem involves different reference directions or large-scale geography, check the model before applying the school rule.

Is the shortest distance always the distance travelled? No. The direct line between two points represents displacement length; the journey may follow several legs. Calculate and label the requested quantity. A route with a right angle often uses Pythagoras for the direct length, but that is a different decision from finding its direction.

If the learner struggles with diagram reading, start with the four cardinal directions and two rays. If the issue is calculation, revisit the right-triangle ratio and check the quadrant before rounding. Bring a sketch showing where north was drawn and where each angle begins. It gives a teacher a useful place to start.

References and further reading

The worked scenes and practice sets are original teaching examples. These references offer formal definitions or documented usage; the connected eduKate guides provide foundations and further study.

Oak National Academy: following a bearing · Oak National Academy: solving bearing problems · Similar triangles for families · Secondary 3 applications of trigonometry

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