We know a polygon is a simple closed figure made up of only line segments. We can classify polygons according to the number of sides or vertices. The simple polygon we know is a triangle. A triangle has three sides and, thus, is a three-sided polygon. A four-sided polygon is called a quadrilateral. A five sided polygon is called a pentagon. In this manner, we can obtain a six-sided polygon called a hexagon, a seven-sided polygon, called a heptagon, and so on. Read more at https://learnnext.com/lesson/CBSE-VIII-Maths-Polygons.htm