Find the area of the triangle with vertices: Q(-1,5,5), R(-2,8,7), S(-3,2,8).

Find the area of the parallelogram with vertices: P(0,0,0), Q(-4,-5,4), R(-4,-3,6), S(-8,-8,10).

Show that A ( -4,3) , B ( -2,6) , C ( 1,4) and D ( -1,1) are verticies of a square . What is the perimeter and the area ?

Find the area of the parallelogram with vertices at A(1,-5,2) B(-8, -13,-5) C(-11,7,5) D(-20, −1, −2) square units.