For what value of p the point `(1,1), (2,3) ,(p,2)` will form right angled triangle

Show that the points (1, 2, -2), (2, 3, -4) and (3, 4, -3) form a right angled triangle.

For what value of alpha ,the points (1,2,3),(2,3,1) and (3,1,alpha) form an equilateral triangle?

Show that the points A(3, -2,1), B(1,-3,5), C(2,1,-4) do not form a right - angled triangle.

Show that the triangle formed by the points A(1, 3), B(3,-1) and C(-5,-5) is a right angled triangle (by using slopes).

For what value of P, points (2,1),(P,-1) and (-1,3) are collinear

Prove that the points (2,-2), (-2, 1) and (5, 2) are the vertices of a right angled triangle. Also find the area of this triangle.

Show that points A(3,-1) , B(-1 , 2) and C (6,3) form an isosceles right -angled triangle when joined .