10 sided 2D shape is called a decagon 20 sided 2D shape is called a icosagon 30 sided 2D shape is a swimming pool 40 sided 2D shape is unknown 50 sided 2D shape is unknown 60 sided 2d shape is unknown 70 sided 2d shape is unknown 80 sided 2d shape is unknown 90 sided 2d shape is unknown 100 sided 2d shape is unknown 110 sided 2d shape is unknown 111 sided 2d shape is unknown 120 sided 2d shape is unknown 130 sided 2d shape is unknown
A seven sided 2D shape is a heptagon.
A 2d nine sided shape is called a nonagon.
As a 2D polygon shape it is an 8 sided octagon.
A 5-sided 2D shape would be a pentagon, pent, meaning 5.
octadecagon is the name of a 2 d 18 sided polygon. The octa part is for 8 and the deca is for 10 since 18=10+8
Any 4 sided 2D shape
a triangle
A 2D shape with forty sides is known as a tentracontagon.
Such a 2D shape is a hexagon, a six sided figure.
triskaidecagon
Dodecagon