If a shape is a quadrilateral, then it has congruent diagonals.

If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram. If a quadrilateral is a rectangle, then it is a parallelogram. If a parallelogram is a rectangle, then its diagonals are congruent. If one angle of a parallelogram is a right angle, then the parallelogram is a rectangle.

Answerhighlands and forests;