W and Z are both 30 because angles on a straight line = 180, the line diagonally top left to bottom right has an intersecting line with angle of 150.
180-150 = 30
this leaves angle Y which is 90-30 as it is a right angle. So angle Y is 60 and to get x, it is 90 due to the right angle. you can prove this by saying angles on a straight line are 180 and 180-(Y+ Z) or 180-(30+60)
