Answer:
∠B = 93°
Step-by-step explanation:
Supplementary angles are such pairs that sum up to 180°. In this case, we are given that ∠A and ∠B are supplementary. This means that the sum of ∠A and ∠B is 180°.
⇒ ∠A + ∠B = 180°
⇒ 87 + ∠B = 180°
⇒ ∠B = 180 - 87
⇒ ∠B = 93°
