What's a Seven Sided Shape Called?

In geometry, a heptagon is a seven-sided polygon or 7-gon.

What is a shape with 1 trillion sides called?

A teragon is a polygon with 1 trillion sides, it has a Schläfli symbol .

What do you call a 11 sided shape?

(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".) ... In geometry, a hendecagon (also undecagon or endecagon) or 11-gon is an eleven-sided polygon.