CONVEX POLYGON

In geometry, a 'convex polygon' is a simple polygon whose interior is a convex set. The following properties of a simple polygon are all equivalent to convexity:

★ Every internal angle is at most 180 degrees.

★ Every line segment between two vertices of the polygon does not go exterior to the polygon (i.e., it remains inside or on the boundary of the polygon).
A simple polygon is 'strictly convex' if every internal angle is strictly less than 180 degrees. Equivalently, a polygon is strictly convex if every line segment between two vertices of the polygon is strictly interior to the polygon except at its endpoints.
Every triangle is strictly convex.
The sum of the interior angles of a regular convex polygon with ''n'' sides is equal to 180°(''n'' - 2).

Contents

Concave polygon

External links

Concave polygon

If a simple polygon is not convex, it is called 'concave'. At least one internal angle of a concave polygon is larger than 180 degrees.
A concave polygon is often called re-entrant polygon (but in some cases the latter term has a different meaning).

External links

★ Definition and properties of convex polygons With interactive animation