Definition

Complementary Angles

Two angles are complementary if the sum of their measures equals 90°90°. When two angles are complementary, each angle is called the complement of the other. For example, angles measuring 58°58° and 32°32° are complementary because 58+32=9058 + 32 = 90. This property provides a useful relationship: if xx and yy represent the measures of two complementary angles, then:

x+y=90x + y = 90

This equation can be used alongside a second relationship between the angles to form a system of equations for solving angle problems.

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Updated 2026-04-29

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