8th grade math help ,pleasepleaseplease answer?! :/?

As this is homework that is supposed to help you, I'll give you a hint. In a right sided triangle, (A^2)+(B^2)=(C^2), where A and B are the sides of the TV, and C is the diagonal. Since the TV is a square, A=B, so the formula is now 2(A^2)=(C^2). You are given C for each TV, so just solve for A to get a side length.