Show that the points A(2,3,-2),B(6,9,-4),C(7,0,-1) and D(3,-6,1) taken in order are the vertices of a parallelogram.

By using the concept of slope, show that the points (-2,-1), (4,0), (3,3) and (-3,2) are the vertices of a parallelogram.

Show that the points A(3,2,1),B(4,5,5),C(4,2,-2) and D(6,5,-1) are coplanar.

Show that the points A(1,3,2),B(-2,0,1) and C(4,6,3) are collinear.

Show that the points (3, -1, -1), (5,-4, 0), (2, 3, -2) and ( 0, 6, -3) are the vertices of a parallelogram*.

Show that the points A(1, 2, 3,), B (-1, -2. -1), C(2, 3, 2) and D(4, 7, 6) are the vertices of parallelogram ABCD but it is not a rectangle.

Show that the points (-6,3,2),(3,-2,4),(5,7,3) and (-13,17,-1) are coplanar.

Show that the points : A (0,- 2), B (3, 1), C (0, 4) and D (- 3, 1) are the vertices of a square ABCD.

Show that the points (4,7,8), (2,3,4),(-1,-2,1) and (1,2,5) taken in order from a parallelogram. Do these points form a rectangle.

Show that the points A(4,5,1), B(0,-1,-1), C(3,9,4) and D(-4,4,4) are coplanar.

Show that the points (1, 2, 3), (-1, -2, -1), (2, 3, 2) and (4, 7, 6) are the vertices of a parallelogram.