Question

Two angles the sum of whose measure is ${90}^{\circ }$ are called ______ angles.

• A. Supplementary
• B. Complementary
• C. Corresponding
• D. None of these

Answer 1

Answer: (B)

Complementary

By definition we know that two angles, the sum of whose measure is ${90}^o$ are called complementary angles.

Then, such angles are called complement of each other.

E.g.: Let the measure of one complementary angle is ${58}^o.$

$\Rightarrow$ Measure of other complementary angle $={90}^o-{58}^o$ $={32}^o.$

$\therefore$ Measure of the complementary angle of ${58}^o={32}^o$.

Hence, ${58}^o$ and ${32}^o$ are complements of each other.

Therefore, option $B$ is correct.