Concave polygon

Concave polygon.png

A concave polygon is a polygon that has an "opening" in it. In other words, there are two points, A, and B, in the interior of the polgon such that a portion of segment $\overline{AB}$ is not in the boundary of the polygon. A concave polygon has at least one reflex angle, or an angle that is greater than $180^{\circ}$.

See also

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