Two angles whose measures add up to 90 degrees are called what?

Two angles whose measures add up to 90 degrees are called what?

• A. Vertical Angles
• B. Complementary Angles
• C. Transversal
• D. Corresponding Angles

Answer: (B)

Two angles whose measures add up to 90 degrees are called complementary. This comes from the idea that a right angle measures 90 degrees, so the two angles together fill that right angle. For example, 30 degrees and 60 degrees are complementary. In a right triangle, the two non-right angles are complementary because they sum to 90. The other terms describe different ideas: vertical angles are opposite angles formed by intersecting lines and are equal to each other, not defined by a sum to 90; a transversal is a line that cuts across two lines, and corresponding angles are those in matching positions when a transversal crosses two lines, which are typically equal rather than summing to 90.

Two angles whose measures add up to 90 degrees are called complementary. This comes from the idea that a right angle measures 90 degrees, so the two angles together fill that right angle. For example, 30 degrees and 60 degrees are complementary. In a right triangle, the two non-right angles are complementary because they sum to 90. The other terms describe different ideas: vertical angles are opposite angles formed by intersecting lines and are equal to each other, not defined by a sum to 90; a transversal is a line that cuts across two lines, and corresponding angles are those in matching positions when a transversal crosses two lines, which are typically equal rather than summing to 90.