The vertices of a parallelogram are A(x1, y1), B(x2, y2), C(x3, y3), and D(x4, y4). Which of the following must be true if parallelogram ABCD is proven to be a rectangle?

The vertices of a parallelogram are Ax1 y1 Bx2 y2 Cx3 y3 and Dx4 y4 Which of the following must be true if parallelogram ABCD is proven to be a rectangle class=