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
What is the missing angle θ below?
The 53° angle and θ are complementary angles. They add up to 90°.
53° + θ = 90°
Subtract the 53° angle from 90°.
θ = 90° − 53° = 37°
The missing angle θ is 37°.
The slider below shows another real example of complementary angles.Open the slider in a new tab