A closed plane figure made up of several line segments that are joined together. The sides do not cross each other. Exactly two sides meet at every vertex. Regular - all angles are equal and all sides are the same length.
Regular polygons are both equiangular and equilateral.
Equiangular - all angles are equal. Equilateral - all sides are the same length. Convex - a straight line drawn through a convex polygon crosses at most two sides . Concave - you can draw at least one straight line through a concave polygon that crosses more than two sides . Polygon Parts Side - one of the line segments that make up the polygon.