 # Sine, cosine rules for SQA National 5 Maths 1. Sine rule
2. Problems with sine rule
3. Cosine rule
4. Problems with cosine rule When solving word problems with the sine rule it is best to draw a picture and label the known angles/side lengths.  When solving word problems with the cosine rule it is best to draw a picture and label the known angles/side lengths. # 1

Use the cosine rule to find angle A, given a = 5, b = 7 and c = 6.

44.4º # 2

Find the length of pole A. Give your answer with two decimal places.

12.45 m # 3

The diagram shows a ladder propped against a slightly slanted wall. Find the angle between the ladder and the wall.

27.7º # 4

A triangle is created using 3 poles. The poles are 20 m, 25 m and 23 m in length. Find the angle between the 20 m and 23 m poles.

70.7º # 5

Two match sticks are held up with their tips against each other. Both match sticks are 5 cm long. The angle between them is 65º. Find the distance between the bottom of the match sticks along the ground.

5.37 cm End of page