An 18 sided polygon is called a Octadecagon or a Octakaidecagon
The name of a 18 sided polygon is Octadecagon.
The name of a 18 sided polygon is Octadecagon.
The name of a 18 sided polygon is Octadecagon.
The name for this polygon is a nonagon,
octadecagon
The name of a 7 sided polygon is Heptagon.
A hendecagon or an undecagon is the name of a polygon which has eleven sides.
Apothem!
Not surprisingly, it is called a side!
"Heptagon" is the name of a 7-sided polygon.
If measured on the inside of the polygon, the it is an interior angle.
An Octadecagon