Question

Which of the following is complement of angle (90° - a)?

• A. a
• B. 180° - a
• C. 90° + a
• D. 180° + a

Answer 1

The correct option is A a

The complement of $({90}^o-a)$ is a.

If the sum of angles is equal to ${90}^o$, they are called complementary angles.

Here, one angle is given to be $({90}^o-a)$.
Let the complement of $({90}^o-x)$ angle be $x$.

So, $({90}^o-a)+x={90}^o$
Then, $x={90}^o-({90}^o-a)x=a$
So, the complement of $({90}^o-a)$ is $a$.