Enneadecagon
A twelve-sided polygon is called a dodecagon.
A Pentagon
It's called a triangle.
Hexagon
Hexagon
DECAGON
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 polygon with five sides is a pentagon.
a pollygon with ten sides is called decagon
A 6 sided hexagon
A 19 sided polygon is called an enneakaidecagon.