## The Lesson

Complementary angles are two angles which add up to a right angle (90°). Two angles that add to 90° are are said to complement each other.## A Real Example of Complementary Angles

Angles of 30° and 60° are complementary angles.
30° + 60° = 90°

## How to Find a Complementary Angle

## Question

What is the missing angle θ below?## Step-by-Step:

# 1

The 53° angle and θ are complementary angles. They add up to 90°.

53° + θ = 90°

# 2

Subtract the 53° angle from 90°.

θ = 90° − 53° = 37°

## Answer:

The missing angle θ is 37°.## Top Tip

## What Types of Angles Are Complementary?

**C**omplementary angles form a

**C**orner.