3. Verify the following:
(i) (0,7,−10),(1,6,−6) and (4,9,−6) are the vertices of an isosceles triangle.
(ii) (0,7,10),(−1,6,6) and (−4,9,6) are the vertices of a right angled triangle.
(iii) (−1,2,1),(1,−2,5),(4,−7,8) and (2,−3,4) are the vertices of a parallelogram.