Pentacontagon

In geometry, a pentacontagon or pentecontagon or 50-gon is a fifty-sided polygon. The sum of any pentacontagon's interior angles is 8640 degrees.
Regular pentacontagon.
A "regular pentacontagon" is represented by Schläfli symbol {50} and can be constructed as a quasiregular truncated icosipentagon, t{25}, which alternates two types of edges.
Area.
One interior angle in a regular pentacontagon is 172°, meaning that one exterior angle would be 7°.
The area of a regular pentacontagon is (with )
and its inradius is
The circumradius of a regular pentacontagon is
Since 50 = 2 × 52, a regular pentacontagon is not constructible using a compass and straightedge, and is not constructible even if the use of an angle trisector is allowed.
Dissection.
Coxeter states that every zonogon (a 2"m"-gon whose opposite sides are parallel and of equal length) can be dissected into "m"("m"-1)/2 parallelograms.
In particular this is true for regular polygons with evenly many sides, in which case the parallelograms are all rhombi. For the "regular pentacontagon", "m"=25, it can be divided into 300: 12 sets of 25 rhombs. This decomposition is based on a Petrie polygon projection of a 25-cube.