Can somebody solve this geometry proof?

You can use the SSS property to show that triangle VWX is congruent to triangle VYX which means that the diagnol VX bisects the angle V and angle X. Similarly it can be shown that the diagnal WY bisects angle W and angle Y. We know that because this is a parralelogram that angle V = 180 - angle X. which means that V + X = 180. If V and X are both bisected, then 1/2 (V + X) = 90. This means that the interior Triangle made by the 2 diagonals VOX must be a right angle. Therefore, WY and VX are perpendicular.