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

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(3,3,3,),\ B(0,6,3),\ C(1,7,7)a n d\ D(4,4,7) are the vertices of a square.

Show that the points A(1,\ -2),\ \ B(3,\ 6),\ \ C(5,\ 10) and D(3,\ 2) are the vertices of a parallelogram.

Show that the points A(1,3,4),\ B(-1,6, 10),\ C(-7,4,7)a n d\ D(-5,1,1) are have vertices of a rhombus.

Show that the points A(1,\ 0),\ \ B(5,\ 3),\ \ C(2,\ 7) and D(-2,\ 4) are the vertices of a parallelogram.

Show that the points A(2,3,5),B(-4,7,-7),C(-2,1,-10) and D(4,-3,2) are the vertices of a rectangle.

Show that the points A(5,\ 6),\ \ B(1,\ 5),\ \ C(2,\ 1) and D(6,\ 2) are the vertices of a square.

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

Show that the points A (5, 6), B(1,5), C(2, 1) and D(6, 2) are the vertices of a square ABCD.

Without using the distance formula, show that the points A (4, 5), B (1, 2), C (4, 3) and D (7, 6) are the vertices of a parallelogram.