A five-sided polygon is called a pentagon.
A thousand-sided polygon is a chiliagon.
hectoctagon is a 108 sided polygon
a hectoenneagon is a 109 sided polygon
The name of a 18 sided polygon is Octadecagon.
The interior angles of a 39 sided polygon add up to (39-2)*180 = 6660 degrees
A five sided polygon is called a pentagon because pentagon means five sided polygon I think.
A 39-sided shape is called a "triacontaenneagon." The name is derived from the Greek prefixes "triaconta-" (meaning thirty) and "-enneagon" (meaning nine-sided polygon). The triacontaenneagon has 39 sides, 39 angles, and 39 vertices.
A 39 sided polygon
A million-sided polygon is called a megagon.
A 12-sided polygon is called a dodecagon.
A 20-sided polygon is called an icosagon.
A 25 sided polygon is called a icosikaipentagon.
A 14 sided polygon is called a tetradecagon.
A 90-sided polygon is called an enneacontagon.
A five-sided polygon is called a pentagon.
A 13 sided polygon is called a Tridecagon also a Triskaidecagon.