十一边形是几何学上所有有11条边

正十一边形是十一边等长、十一角等大的多边形。内角为147.2727°。若边长为，面积。

In geometry, a hendecagon (also undecagon or endecagon) is an eleven-sided polygon or 11-gon. (The name hendecagon, from Greek hendeka "eleven" and gon– "corner", is often preferred to the hybrid undecagon, whose first part is formed from Latin undecim "eleven".)