# StudySquare

# Sine, cosine rules for Edexcel GCSE Maths

This page covers the following topics:

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

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