(C) Prove that the points A (6,9), B (0, 1) and C (-6, -7) align.

prove that the points A(1,-1) B(-4,-8) and C(6,6) are collinear

Show that the points A(6,4) , B(9,7) and C(11,9) are collinear.

Prove that the points A (9,0) , B(9,6) , C (-9 , 6) and D (-9,0) are the vertices of a rectangle .

Prove that the points A (-2,-1) , B (5,4) C (6,7) and D (-1,2) are the vertices of a parallelogram.

Prove that the point A (7, 3), B (9, 6), C (10, 12) and D(8, 9) when joined consecutively produce a parallelogram.

Using vector method prove that the points A(6,−7,−1),B(2,−3,1) and C(4,−5,0) are collinear.

Prove that the points A(4, 0), B(6, 1), C(4, 3) and D(3, 2) are concyclic.

Show that the points A(3,5,1), B(-1,0,8) and C(7,10,-6) are collinear.

Prove that the points (0, 7,-10), (1, 6,-6) and (4,9, - 6) are the vertices of an isosceles triangle.