Inverse sides of a parallelogram are always parallel (by definition) and because of which they will never intersect. The area of a parallelogram is twice the area of a triangle designed by one of its diagonal sides. The area of a parallelogram is also considered to be equal to the magnitude of the vector across the product of two adjoining sides.Rhomboid – It is a quadrilateral whose opposite sides are adjacent and parallel sides are dissimilar, and whose angles are not always right angles.Rectangle – It is a parallelogram along with four angles of equal size (i.e., right angles).Rhombus – It is a parallelogram which consists of four sides with equal lengths.Square – It is a parallelogram with four sides of same and equal length and angles of identical and equal size (right angles).