An 8 sided shape is called an octagon
Not sure about a five sided shap, but a five sided plane shape is called a pentagon.
A Do-decagon.
Undecagon
A heptagon
A nonagon has 9 sides
A pentagon or an irregular pentagon if the sides are unequal in length.
Yes.
A 7 sided shape is an heptagon and sometimes known as a septagon
a 9 sided shape is a nonagon
An eight sided shape is called an octagon.
An 8-sided polygon is called an octagon.
An 8 sided figure is an octagon.