POLYGONS
What is polygon?
-  A polygon is any flat shape with tree or more sides. Polygons are closed figure which means that the lines are closed and not open.

-Alternatively, a polygon can be defined as a closed planar figure that is the union of a finite number of line segments.The term polygon is derived from a Greek word meaning “many-angled”.

-A polygon: Formed by 3 or more segments (sides), no two sides with common endpoints are collinear Each side intersects exactly 2 other sides, one at each end point Endpoints are called a Vertex (vertices).
What are the types of polygons?
Convex and concave
Polygons first fit into two general categories— convex and not convex (sometimes called concave). A polygon is concave if there are two points somewhere inside it for which a segment with these as its endpoints cuts at least 2 of the sides of the polygon. A polygon that is not concave is called convex

Regular polygons

Regular Polygons A regular polygon is a polygon whose sides are all the same length, and whose angles are all the same. The sum of the angles of a polygon with n sides, where n is 3 or more, is 180° × (n - 2) degrees.