Angles X and Y are supplementary. Angle X measures 116.89°, and angle Y measures (m − 10)°. Find m∠Y.

a 63.11°
b 73.11°
c 106.89°
d 126.89°

Since angles X and Y are supplementary, their measures add up to 180°.

We are given that angle X measures 116.89°. Therefore, angle Y must measure:

180° - 116.89° = 63.11°

Therefore, m∠Y is equal to 63.11°.

The correct answer is: a) 63.11°.