ETYM French, from Latin rectus right + angulus angle. Related to Right, and Angle.
A parallelogram with four right angles.
Quadrilateral (four-sided plane figure) with opposite sides equal and parallel and with each interior angle a right angle (90ş). Its area A is the product of the length l and height h; that is, A = l x h. A rectangle with all four sides equal is a square.
A rectangle is a special case of a parallelogram. The diagonals of a rectangle are equal and bisect each other.