It can either be called an Triskaidecagon or a Tridecagon.
Decagon. A decagon is the name of a ten sided shape.
A 10-sided shape is a decagon.
A Pentacontagon is a fifty sided shape ...
Tridecagon
In geometry, a tridecagon (or triskaidecagon) is a 13-sided (and angled) polygon.
The name of a 13 sided polygon is Tridecagon.
triskaidecagon or a tridecagon
It can either be called an Triskaidecagon or a Tridecagon.
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.
triskaidecagon (tri-skade-ka-gon)
tridecagon, but most mathematicians would use "13-gon."
The full name of a 13-sided polygon is a triskaidecagon. However, with polygons of such size, it's common practice to call them n-gons, so in this case the shape would be called a 13-gon.
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 tweleve sided shape is a dodecagon.
Decagon. A decagon is the name of a ten sided shape.
A 10-sided shape is a decagon.