Using vector method, prove that if the diagonals of a parallelogram are equal, then it is a rectangle.

Using vectors prove that the diagonals of a parallelogram bisect each other.

If a parallelogram is cyclic, then it is a rectangle. Justify.

If the diagonal of a rhombus are equal, then the rhombus is a

Show that the diagonals of a parallelogram divide it into four triangles of equal area.

Using dot product of vectors, prove that a parallelogram, whose diagonals are equal, is a rectangle

Prove by vector method that the diagonals of a rhombus bisect each other at right angles.

Prove that the sum of the squares of the squares of tha diagonals of a parallelogram is equal to tha sum of the squares of its sides.

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

By using vectors prove that a quadrilateral is a parallelogram if and only if the diagonals bisect each other.