17.5 Bearings and scale drawings — Practise
Work independently, then check your answers and reasoning.
- Write the three-figure bearing for east.
- Write the three-figure bearing for south-west.
- Write the three-figure bearing for south-east.
- A scale is 1 cm to 4 km. What real distance does 6 cm represent?
- A scale is 1 cm to 5 m. How long is 35 m on the drawing?
- A map scale is 1:25 000. What real distance in metres does 4 cm represent?
- A rectangle is 24 m by 18 m. Work out its diagonal.
- A route goes 24 m east and 18 m north. Find its bearing to the nearest degree.
- A plan uses 1 cm to 5 m. The garden is 20 m by 15 m. Which method finds the real diagonal: scale the drawing, or use Pythagoras on the real lengths? Give a reason, then work it out.
Answers and concise solutions
1. Write the three-figure bearing for east.
Answer: 090 degrees
2. Write the three-figure bearing for south-west.
Answer: 225 degrees
3. Write the three-figure bearing for south-east.
Answer: 135 degrees
4. A scale is 1 cm to 4 km. What real distance does 6 cm represent?
Answer: 24 km
5. A scale is 1 cm to 5 m. How long is 35 m on the drawing?
Answer: 7 cm
6. A map scale is 1:25 000. What real distance in metres does 4 cm represent?
Answer: 1000 m
7. A rectangle is 24 m by 18 m. Work out its diagonal.
Answer: 30 m
8. A route goes 24 m east and 18 m north. Find its bearing to the nearest degree.
Answer: 053 degrees
9. Method choice: scale or Pythagoras
Answer: Both methods agree. The plan is 4 cm by 3 cm, so its diagonal is cm. That represents m, and Pythagoras on the real lengths also gives m.