A convex polygon is one drawn so that

- each interior angle is less than 180 degrees, and

- each line segment between two vertices is either on the boundary or inside the boundary of the polygon.

Here is an example of a convex polygon. It happens to be a regular octagon. A convex polygon does not have to be regular.

This article contains an example of a polygon that is not convex.

- each interior angle is less than 180 degrees, and

- each line segment between two vertices is either on the boundary or inside the boundary of the polygon.

Here is an example of a convex polygon. It happens to be a regular octagon. A convex polygon does not have to be regular.

This article contains an example of a polygon that is not convex.