page_title: Octacontagon
section_title: Dissection
hierarchical_section_title: Octacontagon / Dissection
context_page_description: In geometry, an octacontagon is an eighty-sided polygon. The sum of any octacontagon's interior angles is 14040 degrees.
context_section_description: Coxeter states that every zonogon (a 2m-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 octacontagon, m=40, and it can be divided into 780: 20 squares and 19 sets of 40 rhombs. This decomposition is based on a Petrie polygon projection of a 40-cube.
caption: 80-gon with 3120 rhombs