By method, show that the quadrilateral with vertices A(1,2,-1), B(8,-3,-4), C(5,-1,1),D(-2,1,4) is a parallelogram.

Show that the quadrilateral with vertices A(3,2), B(0,5), C(-3,2), D(0,-1) is a square.

Find the area of the quadrilateral whose vertices are A(2,1),B(0,3),C(-3,4),D(1,-4)

Prove that the quadrilateral with vertices '(1,1),(5,1),(7,8),(3,8)' is a parallelogram.

Find the area of the quadrilateral whose vertices are A(1,1),B(3,4),C(5,-2) and D(4,-7)

Show that the triangle with vertices A (3,5,-4), B (-1, 1,2) C (-5,-5,-2) is isosceles.

Find the area of quadrilateral whose vertices are: A(-3,1),B(-2,-2),D(1,4),C(3,-1)

Show that the quadrilateral ABCD with A(3,1) ,B(0,-2),C(1,1) and D(4,4) parallelogram.

Show that A(1,-2),B(3,4),C(5,10),D(3,2) are the vertices of parallelogram.

By vector method,show that the four points (7,2,-3),(6,1,4),(-3,-4,-1) and (-2,-3,-8) are the vertices of a parallelogram.