Show that the points `(1, 2, 3), (-1, -2, -1), (2, 3, 2) and (4, 7, 6)` 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 a parallelogram ABCD but it is not a rectangle

Verify the following : (-1, 2, 1), (1, -2, 5), (4, -7, 8) and (2, -3, 4) are the vertices of a parallelogram.

Show that four points (1, -2), (3, 6), (5, 10) and (3, 2) are the vertices of a parallelogram.

Show that the points A(7, 3), B(6, 1), C(8, 2) and D(9, 4) taken in that order are vertices of a parallelogram.

The points A(4, 5, 10), B(2, 3, 4) and C(1, 2, -1) are three vertices of a parallelogram ABCD, then

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

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

Prove that the points (0, -1), (6, 7), (-2, 3) and (8, 3) are the vertices of a rectangle.

Show that the points A(1, 2, 7), B(2, 6, 3) and C(3, 10, -1) are collinear.

Show that the points (2, 3, 4), (- 1, - 2, 1), (5, 8, 7) are collinear.