What type of angles add up to 90 degrees?

Complementary angles are defined as two angles whose measures add up to exactly 90 degrees. This concept is fundamental in geometry, where recognizing and working with angle relationships is crucial. For example, if one angle measures 30 degrees, its complement would measure 60 degrees, because 30 + 60 = 90.

In contrast, supplementary angles are those that add up to 180 degrees, while vertical angles are formed by intersecting lines and are always equal, but they do not pertain to a specific sum of 90 degrees. Adjacent angles share a common vertex and side but do not have a requirement to sum to either 90 or 180 degrees. Therefore, complementary angles uniquely match the criterion of summing to 90 degrees.