Octagon.
A five sided 2 dimensional object is called a pentagon.
nonagon
A triangular pyramid.
There are two different names commonly used for a 9 sided figure: a nonagon or, an enneagon.
The name of a 9 sided polygon is Nonagon.
The name of a 9 sided polygon is nonagon or enneagon.
Decagon.
octagon
Octagon.
hendecagon
the Greeks used prefexes up to ten, modernly we have sdded dodecagon for a twelvesided object and undecagon for an eleven sided object so the propor name would be a 27 sided object.
A hexakaidecagon (hexadecagon).
Decagon
A five sided 2 dimensional object is called a pentagon.
Nonagon is the name of a 9 sided shape. The US Steel Tower in Pittsburgh, Pennsylvania is a nonagon.
HEXADECAHEDRON is the correct name for a 16 sided 3D object