Answer:
∠YXZ = 58°
Step-by-step explanation:
Use the angle sum theorem and the given relations.
∠WXY +∠WXV = ∠YXV
∠WXY +(11° +3∠WXY) = 139°
4∠WXY = 128° . . . . . subtract 11°
∠WXY = 32° . . . . . . . divide by 4
Similarly, ...
∠WXY +∠YXZ = 90°
∠YXZ = 90° -∠WXY = 90° -32°
∠YXZ = 58°
