A twelve-sided polygon is called a dodecagon.
A polygon with five sides is a pentagon.
Enneadecagon
It's called a triangle.
Hexagon
DECAGON
Hexagon
Quindecagon or pentadecagona 15 sided pollygon is called a Pentadecagon, it has interior angles of 156 degrees each
A four sided polygon is a quadrilateral.
A 6 sided hexagon
a pollygon with ten sides is called decagon
A five sided polygon is called a pentagon because pentagon means five sided polygon I think.