9.6 Polygons

The document defines and classifies different types of polygons. It states that a polygon is a plane figure formed by three or more line segments. It then defines triangles, quadrilaterals, pentagons, hexagons, and octagons as polygons with 3, 4, 5, 6, and 8 sides, respectively. It also defines regular polygons as those with equal side lengths and angle measures, and diagonals as segments connecting vertices within a polygon other than the sides.