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A Regular Polygon with 82 sides: Area, Perimeter, Interior and Exterior Angles, Inradius, Circumradius



A regular polygon with 82 sides where the length of each side is 8 units. The units may either be inches or cm or km or miles: any unit of length.

You are given a Regular Polygon with 82 sides. What are the interior angles and exterior angles? 
If the length of each side is 8 units, what is the perimeter, area, circum-radius and in-radius of the polygon?

n = 82

Perimeter of a polygon with 82 sides = (side length) x 82 = 656 units

Area of a polygon with 82 sides = (n x Sidecot (Π/n))/4 = (n x 8cot (Π/82))/4 = 34228.29 square units

Sum of the interior angles of a polygon with 82 sides = 
 (n-2) x 180 degrees =  (82-2) x 180 degrees = 14400 degrees

Interior Angle of a polygon with 82 sides = (n-2) x 180/n degrees = (82-2) x 180/82 degrees = 175.6 degrees 

Exterior angle of a polygon with 82 sides = 180 - Interior Angle = 180 - 175.6 = 4.39 degrees

Inradius = Radius of In-circle = (side length) x cot (Π/82) = 8 x cot 2 = 208.7 units

Circumradius = Radius of Circum-circle = (side length) x cosec (Π/82) = 8 x cosec 2 degrees = 208.86 units

Symmetry Group = D82  82 rotational symmetries and 82 reflection symmetries. The "D" stands for di-hedral. 




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