a 28 sided figure i believe is a duoctogon
Icosikaihenagon
a 24 sided polygon is a icosikaitera.
Octagon
An octagon
an octagon
Icosahedron is the shape, but it's just called 20 sided if you want to buy one.
A regular twenty-sided polygon is called an icosagon.
A twenty-eight sided figure is called an Icosikaioctagon. The word icos refers to the number twenty and the word octagon refers to eight. When combined, they form the word Icosikaioctagon.
A twenty sided, 2D figure is called an icosagon.
The name for a 57 sided shape is derived by combining the name for a 50 sided shape with the name for a 7 sided shape. A 57 sided shape is called a pentacontaheptagon.
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.
A two-dimensional shape with twenty sides is an icosagon. A three-dimensional object with twenty sides is an icosahedron.