CK-12-Geometry-Second-Edition

http://www.ck12.org Chapter 1. Basics of Geometry

Classifying Polygons

Whether a polygon is convex or concave, it can always be named by the number of sides. See the chart below.

TABLE1.2:

Polygon Name Number of Sides Number of Diagonals Convex Example

Triangle 3 0

Quadrilateral 4 2

Pentagon 5 5

Hexagon 6 9

Heptagon 7 14