500
Show that the vertices represent the vertices of a parallelogram. P(5,0) Q(2,9) R(-6,6) S(-3,-3)
Since slope of segment PS=3/8=slope of segment QR, segment PS is parallel to segment QR. Since slope of segment PQ=-3 = slope of segment SR, Segment PQ is parallel to segment SR. Then, PQRS is a parallelogram by definition.