Question

determining angle measures. let (mangle a = 40^{circ}). if (angle b) is a complement of (angle a), and (angle c) is a supplement of (angle b), find these measures. (mangle b=)(mangle c=)

Explanation:

Step1: Find measure of ∠B

Complementary angles sum to 90°. So $m\angle B=90 - m\angle A$.
$m\angle B = 90 - 40=50$

Step2: Find measure of ∠C

Supplementary angles sum to 180°. So $m\angle C=180 - m\angle B$.
$m\angle C = 180 - 50 = 130$

Answer:

$m\angle B = 50$
$m\angle C = 130$