The 'poly-' prefix simply means 'multiple', so a polygon is a shape with multiple sides, in the same way that 'polygamy' means multiple spouses. There are names for many different types of polygons, and usually the number of sides is more important than the name of the shape.

What is a shape with 11 sides called?

In geometry, a hendecagon (also undecagon or endecagon) or 11-gon is an eleven-sided polygon. (The name hendecagon, from Greek hendeka "eleven" and –gon "corner", is often preferred to the hybrid undecagon, whose first part is formed from Latin undecim "eleven".)

What is 13 sided shape called?

A 13-sided polygon, sometimes also called the triskaidecagon.