Sum of angles in a quadrilateral is 360 degrees: visual proof Learn more 4 non-collinear points forming a quadrilateral Learn more Exterior angles of a quadrilateral is 180 degrees Learn more Interior and exterior angles of a quadrilateral Learn more Angle measures in a quadrilateral Learn more Rectangle PQRS Learn more Parallelogram ABCD Learn more Square PQRS Learn more Rhombus PQRS Learn more Quadrilateral family Learn more