The inside angle for B, which is labeled x is the same as the outside angle of D which is labeled as 72, so we know x = 72.
In a parallelogram two angles next to each other equal 180, so angle A and angle B equal 180.
We know B = 72, so A = 180-72 = 108
Angle A is divided in 2 by angle y, so y = 108/2 = 54
Answers: x = 72
Y = 54