# Convex and Concave Polygons

In geometry, a polygon can be either **convex** or **concave**.

## Convex polygons

A **convex polygon** is a polygon with the following properties:

- Every internal angle is less than 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).
- If any vertical or horizontal axis intersects it at most twice.

## Concave polygons

A polygon that is not convex is called **concave**. A concave polygon will always have an interior angle with a measure that is greater than 180 degrees.

It is possible to cut a concave polygon into a set of convex polygons.