Skip to content

Course home

Angles

Angles

Angles on a straight line add to 180°

Example 1: Find the size of angle a

angles 1

Angles on a straight line add to 180°
a + 130° = 180°
a = 50°

Example 2: Find the size of angle b

angles 2

Angles on a straight line add to 180°
b + 90° + 65° = 180°
b + 155° = 180°
b = 25°

Try these:

Angles around a point add to 360°

Example 3: Find the size of angle e

angles 19

Angles around a point add to 360°
e + 295° = 360°
e = 65°

Example 4: Find the size of angle f

angles 20

Angles around a point add to 360°
f + 131° + 108° + 52° = 360°
f + 291° = 360°
f = 69°

Try these:

Angles in a triangle add to 180°

Example 5: Find the size of angle j

angles 33

Angles in a triangle add to 180°
j + 71° + 53° = 180°
j + 124° = 180°
j = 56°

Example 6: Find the size of angle k

angles 34

Here we have an isosceles triangle. In an isosceles triangle two angles (and two sides) are equal.
There are lines on two of the sides to show that they are equal. The other side of an isosceles triangle is called the base.
The angles at the base of an isosceles triangle are equal. This means we have two 58° angles.

k + 58° + 58° = 180°
k + 116° = 180°
k = 64°

Example 7: Find the size of angle m

angles 35

We have another isosceles triangle. This time the missing angle is at the base.

m + m + 32° = 180°
2m = 148°
m = 74°

Try these:

PreviousNext

How was this guide?

Teach Genie

Review Angles by teaching Genie

Teach it back in your own words, spot gaps, and remember it better.

Start teaching
Genie and Baby Genie

Questions

Put it into practice with exam-style questions

27 exam-style questions

Practice questions

Question 1

1 mark

In the space below draw an angle of 75∘75^\circ75∘. Label the angle PPP.

Flashcards

Remember key concepts with flashcards

20 flashcards

Practice flashcards

An angle is measured in [     ]; the point where its arms meet is the [     ].

Angles Revision Guide

  1. GCSE
  2. /Maths
  3. /Angles

Revision notes for AQA GCSE Maths Angles. Open the guide for explanations and worked examples. Written against the AQA GCSE Maths (8300) specification, so the content matches what's examinable rather than general Maths background.

Practise questions

1 of 3

Two angles are on a straight line. One angle is 118∘118^\circ118∘. What is the size of the other angle?

Practise questions

1 of 3

Two angles are on a straight line. One angle is 75∘75^\circ75∘. What is the size of the other angle?

Practise questions

1 of 3

Four angles meet at a point. Three of them are 85∘85^\circ85∘, 110∘110^\circ110∘ and 95∘95^\circ95∘. Find the fourth angle.

Practise questions

1 of 3

Two angles, x and 65∘65^\circ65∘, lie on a straight line. Find the value of x.

Practise questions

1 of 3

A triangle has angles of 47∘47^\circ47∘ and 68∘68^\circ68∘. Find the third angle.

Practise questions

1 of 3

Two angles are on a straight line. If one angle measures 75∘75^\circ75∘, what is the size of the other angle?