Prove that a cyclic parallelogram is a rectangle.

Prove that a cyclic rhombus is a square

Statement 1: If | vec a+ vec b|=| vec a- vec b|,t h e n vec aa n d vec b are perpendicular to each other. Statement 2: If the diagonal of a parallelogram are equal magnitude, then the parallelogram is a rectangle.

Show that the bisectors of angles of a parallelogram form a rectangle.

In the adjacent figure ABCD is a parallelogram ABEF is a rectangle show that DeltaAFD~=DeltaBEC .

In parallelogram ABCD, diagonals AC and BD are equal. Find the measure of angle ABC and prove that the quadrilateral ABCD is a rectangle.

State whether the statements are True or False. (vi) All parallelograms are rectangles

Prove that the parallelogram circumscribing a circle is a rhombus.

Show that the points A(1,2,3) ,B(-1,-2,-1) ,C(2,3,2) and D(4,7,6) are the vertices of a parallelogram ABCD but it is not a rectangle

Using vectors, prove that the parallelogram on the same base and between the same parallels are equal in area.

Prove that each diagonal of a parallelogram divides it into two congruent triangles.