What is the name of polygons that has hundredths sides?

Answer 1

A polygon that has 100 sides is referred to as a hectogon.

Traditionally with dealing with polygons with enough sides to move beyond the normal names, it's clearer to simply refer to it as an n-sided polygon. In this case you would say "a 100-sided polygon." The reason for this is describing a 972 sided polygon, for example, becomes the confusing "nonahectahepacontakaidigon," (I kid you not) which either written out or spoken out loud conveys little meaning without considerable effort on the part of the audience. "A 972-sided polygon" is far easier to digest.