The "proper" name is icosiheptagon. Most people, including mathematicians, will use 27-gon since that effectively communicates the size of the polygon. But, if you want to appear pretentious or be obfuscatory, by all means use the Greek prefices.
The name of a 51 sided polygon is Pentaconhenagon. The name of a 52 sided polygon is Pentacondigon. The name of a 53 sided polygon is Pentacontrigon. The name of a 54 sided polygon is Pentacontetragon. The name of a 55 sided polygon is Pentaconpentagon. The name of a 56 sided polygon is Pentaconheptagon. The name of a 57 sided polygon is Pentaconhexagon. The name of a 58 sided polygon is Pentaconoctagon. The name of a 59 sided polygon is Pentaconenneagon.
The name of a 12 sided polygon is Dodecagon.
A 8 sided polygon is called a octagon.
The name of a 19 sided polygon is enneadecagon.
The name of a 15 sided polygon is Pentadecagon.
the sum of the interior angles in a 27 sided polygon is 4500.
The name of a 51 sided polygon is Pentaconhenagon. The name of a 52 sided polygon is Pentacondigon. The name of a 53 sided polygon is Pentacontrigon. The name of a 54 sided polygon is Pentacontetragon. The name of a 55 sided polygon is Pentaconpentagon. The name of a 56 sided polygon is Pentaconheptagon. The name of a 57 sided polygon is Pentaconhexagon. The name of a 58 sided polygon is Pentaconoctagon. The name of a 59 sided polygon is Pentaconenneagon.
The name of a 12 sided polygon is Dodecagon.
A 8 sided polygon is called a octagon.
name of 4000 sided polygon
27-agon
A 27-sided polygon would be called an icosiheptagon.
The name of a 19 sided polygon is enneadecagon.
The name of a 15 sided polygon is Pentadecagon.
The name of a 7 sided polygon is Heptagon.
The name of a 200 sided polygon is dihectagon.
The name of a 9 sided polygon is Nonagon.