# Supplementary Angles

## Supplementary Angles

Supplementary angles are two angles which add up to a straight angle (180°).

Two angles that add to 180° are are said to supplement each other.

## A Real Example of Supplementary Angles

Angles of 100° and 80° are supplementary angles.

100° + 80° = 180°

## How to Find a Supplementary Angle

### Question

What is the missing angle θ below?

### Step-by-Step:

# 1

The 56° angle and θ are supplementary angles. They add up to 180°.

56° + θ = 180°

# 2

Subtract the 56° angle from 180°.

θ = 180° − 56° = 124°

### Answer:

The missing angle θ is 124°.