The names of polygons with 40 sides - Tetracontagon.
360/9 = 40 degrees
The name of a 40 sided polygon is Tetracontagon.
The sum of the interior angles of a convex polygon with n sides is given by (n-2)x180o. So for a 40 sided polygon n=40; thus (40-2)x180o = 38x180o = 6840o.
It looks like a circle
10 sided 2D shape is called a decagon 20 sided 2D shape is called a icosagon 30 sided 2D shape is a swimming pool 40 sided 2D shape is unknown 50 sided 2D shape is unknown 60 sided 2d shape is unknown 70 sided 2d shape is unknown 80 sided 2d shape is unknown 90 sided 2d shape is unknown 100 sided 2d shape is unknown 110 sided 2d shape is unknown 111 sided 2d shape is unknown 120 sided 2d shape is unknown 130 sided 2d shape is unknown
I reckon, if a 70 sided shape is called a heptacontagon, and a 50 sided shape is called a pentacontagon, then a 40 sided shape might be called a quadracontagon, or something along those lines.
tetracontagon
41.
tetracontagon
It was a quadrahedron
A nine sided shape that is called a regular nonagon.
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The names of polygons with 40 sides - Tetracontagon.
It is called Tetracontagon.
Interior: 140 Exterior: 40
40-gon.