This document defines and describes different types of polygons. A polygon is a flat shape formed by three or more straight line segments that are connected and do not intersect except at endpoints. Polygons are named based on the number of sides, such as triangles having 3 sides, quadrilaterals having 4 sides, and pentagons having 5 sides. Polygons can be either convex, where the interior angles add up to more than 180 degrees, or concave, where at least one interior angle is greater than 180 degrees. Special types of polygons include equilateral, equiangular, and regular polygons which have consistent side lengths, interior angles, or both.