If the points (1,2),(3,-4),(5,-6),(c,8) are concyclic then find c

'Prove that the points (1,2),(3,-4),(5,-6) and (11,-8) are concyclic

If the points (2, 0), (0, 1), (4, 5)and (0, c) are concyclic, then the value of c, is

Prove that the points (1,-6), (5,2) , (7,0) and (-1,-4) are concyclic. Find the radius of the circle .

Show that the points (7,5),(6,-2),(-1,-1) and (0,6) are concyclic.Also find theradius and the centre of the circle on which they lie.

If the four points (0,0),(1,1),(5,-5) and (6,lambda) are concyclic,find the value of lambda

Show that the points (1,1),(-6,0),(-2,2) and (-2,-8) are concyclic.

Show that the four point (4,6),(-3,5),(5,-1) and (1,7) are concyclic.

If the points A(3,2,-4),B(9,8,-10) and C(5,4,-6) are collinear,find the ratio in which C(5,4,-6) AB.

The distinct points A(0,0),B(0,1),C(1,0), and D(2a,3a) are concyclic than

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