## Nonagon

The unconstructible regular Polygon with nine sides and Schläfli Symbol . It is sometimes called an Enneagon.

Although the regular nonagon is not a Constructible Polygon, Dixon (1991) gives several close approximations. While the Angle subtended by a side is , Dixon gives constructions containing angles of and .

Madachy (1979) illustrates how to construct a nonagon by folding and knotting a strip of paper.