A 4-sided flat shape with straight sides where opposite sides are parallel. Also: • opposite sides are equal in length, and. • opposite angles are equal (angles "a" are the same, and angles "b" are the same) NOTE: Squares, Rectangles and Rhombuses are all Parallelograms. An parallelogram is a quadrilateral shape. The interior angles of an parallelogram is 360 degrees. The sum of the exterior angles are always going to be 360 degrees.