A quadrilateral is a geometrical shape which has four sides. There are four angles in a quadrilateral. The sum of measure of all the four angles of a quadrilateral is 360 degrees. The perimeter of a quadrilateral can be found by adding the measures of all the sides. The quadrilateral with opposite sides equal and parallel are called parallelogram. A square is a quadrilateral whose all sides are equal and opposite sides are parallel. Moreover, rectangle is a quadrilateral whose opposite sides are equal and parallel.
