Question

1. choose the best answer. which is the best definition for complementary angles? two angles that share a common vertex and one common side but have no common interior points. two angles in which the sum of their measures equals 90°. two angles in which the sum of their measures equals 180°. pair of adjacent angles whose noncommon sides are two opposite rays that form a straight line.

Explanation:

To determine the best definition for complementary angles, we recall the definition: Complementary angles are two angles whose sum of measures is \(90^\circ\). Let's analyze each option:

• Option 1: Describes adjacent angles with a common vertex and side (but no common interior points), which is the definition of adjacent angles, not complementary.
• Option 2: Two angles summing to \(180^\circ\) are supplementary angles, not complementary.
• Option 3: Two angles summing to \(90^\circ\) matches the definition of complementary angles.
• Option 4: Two angles summing to \(180^\circ\) are supplementary angles.
• Option 5: Describes a linear pair (adjacent angles forming a straight line, sum to \(180^\circ\)).

Answer:

The option (assuming the third option is labeled, for example, C) C. Two angles in which the sum of their measures equals \(90^\circ\)