An angle is formed by two rays with a common endpoint called the vertex. Angles are measured in degrees and can be acute, right, obtuse, straight, or reflex depending on their measure. Two angles are complementary if their measures sum to 90 degrees, and supplementary if their measures sum to 180 degrees. The complement of an angle is 90 degrees minus its measure, while the supplement is 180 degrees minus its measure.

5. ANGLES