The Lesson

Explementary angles are two angles which add up to a full angle (360°).

A Real Example of Explementary Angles

Angles of 240° and 120° are explementary angles.
240° + 120° = 360°

How to Find an Explementary Angle

Question

What is the missing angle θ below?

Step-by-Step:

1

The 160° angle and θ are explementary angles.
160° + θ = 360°

2

Subtract the 160° angle from 360°.
θ = 360° − 160° = 200°

Answer:

The explementary angle is 200°.

Lesson Slides

The slider below shows another real example of explementary angles.