# Calculate the Unknown Angle in a Triangle

In this worksheet, students will use their knowledge of the properties of a triangle to evaluate unknown angles.

Key stage:  KS 2

Curriculum topic:   Geometry: Properties of Shapes

Curriculum subtopic:   Compare Shape Properties

Popular topics:   Angles worksheets, Geometry worksheets

Difficulty level:

#### Worksheet Overview

In this activity, we will learn how to calculate the unknown angle in a triangle.

Remember: The angles in any triangle will always add up to a total of 180°

This fact will help us to calculate any missing angles.

We can simply subtract the known angles from 180 to find the missing angle.

Let's try an example question together.

Example

Calculate the unknown angle in this triangle.

The angles in any triangle add to 180°

Angle = 180° - 54° - 64° = 62°

The unknown angle is 62°

Now it's time to try some questions like this yourself.

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