A 2-dimensional plain polygon is called a 'DECAGON'.
Here are the names for 2-dimensional polygons, up to ten sides.
3 Trigon ( triangle)
4 Tetragon ( Quadrilateral)
5 Pentagon
6 Hexagon
7 Heptagon
8 Octagon
9 Nonagon
10 Decagon.
NB
The suffix '--gon' indicates a 2-dimensional figure.
The prefixes ' tri--- (etc))' are from their Latin roots.
NNB The suffix '---hedron- indicates a 3-dimensional object. . e.g. 'Tetrahedron'. a four sides 3-dimensional object. (commonly referred to as a 'triangular based pyramid).
you call a seven sided shape a heptagon.
A 30 sided shape is called a Triacontagon.
this shape is called a Pentacontagon
A Tetraicosaterapentatetracontapenhectogigahenicosapenhectomegapentadecadihectohilliahexapenhectogon. Wow, that is long!
A 10 sided shape is called a decagon
you call a seven sided shape a heptagon.
10 sided shapes are known as decagons.
A 10-sided shape is a decagon.
An 11 sided shape is an Eptogon
A 10-sided shape is called a decagon.
10 sided shape: Decagon
A 12-sided shape is called a dodecagon.
A 30 sided shape is called a Triacontagon.
A nine sided shape or polygon is called a nonagon.
A seven sided shape is called a heptagon.
a 10000 sided shape is a myriagon some people call polygons: 10-gon 100-gon 1000-gon and so on
A two dimensional 10 sided shape is a decagon.