Answer: The correct option is (C) 63°.
Step-by-step explanation: Given that two angles A and B are supplementary and m∠A = 117°.
We are to find the measure of angle B.
We know that
two angles are said to be supplementary if the sum of their measures is 180°.
So, for angles A and B, we must have
\(m\angle A+m\angle B=180^\circ\\\\\Rightarrow 117^\circ+m\angle B=180^\circ\\\\\Rightarrow m\angle B=180^\circ-117^\circ\\\\\Rightarrow m\angle B=63^\circ.\)
Thus, the measure of angle B is 63°.
Option (C) is correct.
