What does it mean for two angles to be complementary?

Two angles are defined as complementary when their measures add up to 90 degrees. This means that if you have one angle measuring, for example, 30 degrees, its complementary angle would measure 60 degrees, since 30 + 60 = 90. This concept is crucial in various areas of geometry and helps in solving problems related to angle relationships, especially in right triangles where complementary angles are often encountered.

Understanding complementary angles can also aid in recognizing patterns and relationships in various geometric figures, enhancing overall spatial reasoning and problem-solving skills in mathematics. The other options do not accurately reflect the definition of complementary angles, as they pertain to different angle relationships or conditions.