Show that the points (3,2,2), (-1,4,2), (0,5,6), (2,1,2) lie on a sphere whose centre is (1,3,4). Find the also its radius.

Show that the points (9, -2), (-5, 12) and (-7, 10) lie on that circle whose centre is the point (1, 4)

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

Find the equation of a sphere whose centre is (3,1,2) radius is 5.

Find the equation of a sphere whose centre is (3,1,2) radius is 5.

Show that the points A(1, 0), B(2, -7), C(8, 1) and D(9,-6) all lie on the same circle. Find the equation of this circle, its centre and radius.

Show that the points (4,7,8),(2,3,4),(-1,-2,1) ,(1,2,5) are the vertices of a paralelogram.

Show that the points (-3, 2), (2, -3) and (1, 2 sqrt(3) ) lie on the circumference of that circle, whose centre is origin.

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

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(0,4,3) , B(-1,-5,-3), C(-2,-2,1) and D(1,1,1) are coplanar. Also find the equation of the plane in which these points lie.