The angle of YWZ is equal to the angle of YWX, and angle WYX is also a right angle due to the congruency of segments WZ and WX.
Every triangle has an angle total of 180 degrees, so angle WXY is equal to
180 - (WYX + YWX)
180 - (90 + 17)
73
Angle WXY has an angle value of 73 degrees.