Question

angle b measures $60^\circ$. what is the measure of the angle that is complementary to angle b?
$30^\circ$
$60^\circ$
$120^\circ$
$180^\circ$

Explanation:

Step1: Recall complementary angle rule

Complementary angles sum to $90^\circ$.

Step2: Calculate unknown complementary angle

Let $x$ = complementary angle.
$x = 90^\circ - 60^\circ$

Answer:

30°