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.

Answer

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.