Octagon

An octagon is a polygon that has eight sides. The internal angle at each vertex of a regular octagon is 135?. The area of a regular octagon of side length a is given by

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:A = 2a^2 cot rac{pi}{8} = 2(1+sqrt{2})a^2 simeq 4.82843 a^2.

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A regular octagon is constructible with straightedge and compass. To do so, follow steps 1 through 18 of the animation, noting that the compass radius is not altered during steps 7 though 10.

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Polygon: :For other use please see Polygon (disambiguation)...

Eight: REDIRECT 8_(number)...

Angle: This article is about angles in geometry. For other articles, see Angle (disambiguation)...

Octagon related Images and Photos (experimental)

The Octagon	UFC Octagon Necklace	15'' Octagon Wood Wall Sign	The Octagon 1980
Octagon Girl Replica Uniform Bottom - Red	Octagon Girl Replica UFC Uniform Top - Black	Octagon Girl Replica Uniform Bottom - Black	Men's Octagon Ring - Black
UFC Octagon Girl Replica Uniform Top [Red]	UFC 3D Octagon Coffee Mug	Arianny Celeste UFC Octagon Girl	UFC Electronic Reaction Octagon Playset