Endecagon or hendecagon.
An undecagon has 11 sides
hendecagon
An endecagon
A million sided shape shape is called a megagon.
There is no such thing as a 1 sided shape nor a two sided shape.
An octagon is an 8 sided 2 dimensional shape. A cylinder with the base of a hexagon (6 sided shape) would be an 8 sided 3 dimensional shape.
An 11 sided shape is an Eptogon
An 11-sided 3D shape is a hendecahedron.
In geometry, a hendecagon is an 11-sided polygon.
undecagon.
hendecagon
a henagon is an 11 sided 2-D shape and a 3-D is called an hendecahedron.
hendecagon
hendecagon
An endecagon
it's a 11-sided shape
Hendecahedron
Hendecagon.