∠YXZ=58°
Further explanation
Triangles are flat fields bounded by 3 intersecting sides and 3 angles
This side can be the same length or different.
If at an angle there is an angle of 90 degrees, this triangle is said to be a right angle
∠WXV+∠WXY=∠YXV
∠WXV+∠WXY=139°
∠WXV=11+(3.∠WXY)
11+(3.∠WXY)+∠WXY=139°
11+4∠WXY=139°
4∠WXY=128°
∠WXY=32°
∠WXY+∠YXZ=90°
32°+∠YXZ=90°
∠YXZ = 90°-32°=58°