Take into account that the measure of the angle XYZ is the same that angle ZWY:
m∠XYZ = M∠ZWY = 105°
next, consider the sum of the interior angles of the parallelogram is 360°, moreover, angle WZY and angle WXY are congruent.
Then, you have:
2m∠XYZ + 2m∠WZY = 360°
solve the previous equation for m∠WZY:
2m∠WZY = 360 - 2m∠XYZ
2m∠WZY = 360 - 2(105)
2m∠WZY = 360 - 210
2m∠WZY = 150
m∠WZY = 150/2
m∠WZY = 75
Hence, the measure of the angle WZY is 75°
