a nonagon or a hendecagon
It is called a triangle.
Four sided figures are called quadrilaterals. They are usually squares, rectangles, trapizoids, etc..
11-sided QuadrilateralAn 11-sided quadrilateral is called a hendecagon.
An 11 sided shape is an Eptogon
the 11 sided polygon is undecagon
The name of a 11 sided polygon is Hendecagon.
The name of a 11 sided polygon is Hendecagon.
The name of a 11 sided polygon is Hendecagon.
An 11 sided figure is called a hendecagon, an undecagon, or a 11-gon.
An 11 sided polygon is a hendecagon and a 12 sided polygon is a dodecagon
An 11-sided polygon is called a hendecagon.
An 11-sided 3D shape is a hendecahedron.