The midpoint of the bottom side a square is joined to the ends of the top side and extended by the same length. The ends of these lines are joined and perpendiculars are drawn from these points to the bottom side of the square extended:'(##VPU_HSS_MAT_IX_C07_E01_003_Q01##)'
a) Prove that the rilateral obtained thus is also a square.
b) Explain how we can draw a square with two corners on the dlaineter and the others on a sëmicircle, as shown in the picture.