Bearings

A bearing gives a direction as an angle measured clockwise from north, always written with three figures. So east is 090° and south-west is 225°.

Key facts

  • Start at north, measure clockwise.
  • Always three figures: 045°, not 45°.
  • Back bearing: add or subtract 180°.
  • Use angle facts (parallel north lines) to find missing bearings.

Worked examples

Example 1

The bearing of B from A is 070°. Find the bearing of A from B.

  1. The north lines at A and B are parallel.
  2. Co-interior angles: the angle at B from north round to A is 70° + 180°. 070 + 180 = 250°

Answer: 250°

Example 2

What is the bearing of north-west?

  1. West is 270° and north-west is halfway between west and north. 270 + 45 = 315°

Answer: 315°