Nonagon.
a pentagon.
quadrilateral
hexagon
It's probably a circle, because some people view it as a 0 sided figure, but some people view it as a 1 sided figure.
1200 sided figure is chiliadihectagon
A 17 sided figure is a heptadecagon.
octogon
hexagon
icosikaihena
Nonagon
it is a Dodecagon
Nonagon.
a pentagon.
octogon an octagon
icosagon icosagon
quadrilateral