It is not possible that each angle of a quadrilateral be $90°$.

Three angles of a quadrilateral are of $80°$ each. Determine the fourth angle.

If in a quadrilateral, only one pair of opposite sides is parallel, then such a quadrilateral is called _____.

Each angle of a rectangle is of _____ degrees.

A parallelogram in which each angle is of $90°$ and all sides are of equal lengths is called _____.

A quadrilateral whose all sides are equal is called _____. [parallelogram/ rectangle/ rhombus/ trapezium]

A rectangle is a parallelogram.

Every parallelogram is a rectangle.

Every Rhombus is a square.