Q1: a point Pis 12 kilometers due north of another point Q.The bearing of a lighthouse, R, from P is 135 and, fro Q, it is 120. calculate the distance of PR.
1. Draw a sketch of the described situation (see attachment)
2. Bearings are measured from the North clockwise. So N = 0°, E = 90° etc.
3. You have a triangle QPR. You know all three angles and one leg. So use Sine rule to calculate the line PR:
5. Use Sine rule:
. Solve for PR.