Dodecagon
A dodecagon is a polygon that has twelve sides. A regular dodecagon has twelve internal angles of 150 degrees each.
A twelve sided polygon is called a dodecahedron. No, that is a twelve faced solid (3-D) object. A 12 sided polygon is a dodecagon.
Pentagon
The name of a 12 sided polygon is Dodecagon.
name of 4000 sided polygon
A 8 sided polygon is called a octagon.
The name of a 9 sided polygon is Nonagon.
The name of a 19 sided polygon is enneadecagon.
The name of a 17 sided polygon is Heptadecagon.
The name of a 8 sided polygon is Octagon.
The name of a 10 sided polygon is Decagon.
The name of a 14 sided polygon is Tetradecagon.