Description: Sal discovers attributes and features of four-sided shapes, including parallelograms, rhombuses, rectangles, and squares. What I wanna talk about in this video is shapes with four sides, and the mathy word for shapes with four sides is quadrilateral. So a parallelogram is a quadrilateral, and as we learn more math, we'll learn other ways of thinking about this. It's a quadrilateral where opposite sides are parallel.*Teacher Advisor is 100% free.