If you wish to communicate information, I suggest you call an 89-sided polygon an 89-gon (for example). Although there is a prefix for 89 it is best to keep it simple. Not only is the use of long Greek prefices pretentious, you will only annoy the reader who will probably have to consult a dictionary.
Having said that, if you do want to be pretentious or obfuscate, you can use the link below for polygons with up to 999 sides.
pentagon
a quadrilateral, or Tetragon, or Quadrangle
no. only regular polygons do
regular polygons are the ones that all sides are equal
Polygons are plane closed figures bounded by straight lines. There cannot be polygons with fewer than 3 sides.
You can name the sides any way you like.
nonacontagon
Hexagons
113
It means many sides
pentagon
polologous
Shapes with straight sides are called polygons
Quadrilaterals are polygons with four sides. Triangles are polygons with three sides.
a quadrilateral, or Tetragon, or Quadrangle
Regular polygons.
nonagon(also called an enneagon)