Hendecagon

The hendecagon, or heng, is a polygon with 11 sides. A regular hendecagon has equal sides and equal angles.

Vertex coordinates
Coordinates for a heptagon of edge length 2sin(π/11), centered at the origin, are:


 * (1, 0),
 * (cos(2π/11), ±sin(2π/11)),
 * (cos(4π/11), ±sin(4π/11)),
 * (cos(6π/11), ±sin(6π/11)),
 * (cos(8π/11), ±sin(8π/11)),
 * (cos(10π/11), ±sin(10π/11)).