RS Aggarwal Solutions for Class 6 Chapter 17 “Quadrilaterals”, In Euclidean plane geometry, a quadrilateral is a polygon with four edges and four vertices. Other names for quadrilateral include quadrangle, tetragon, and 4-gon. A quadrilateral with vertices. Mobiles, laptops, computers, books, copies, chart papers etc. are examples of Quadrilaterals. A simple closed figure bounded by four line segments is called a Quadrilateral. Concepts related to quadrilaterals are convex and concave quadrilaterals, interior and exterior of a quadrilateral, angle sum property of a quadrilateral, various types of quadrilaterals such as trapezium, parallelogram, properties of a parallelogram, rhombus, properties of a rhombus, rectangle, properties of rectangle, square, properties of a square.