Octagon
An octagon or 8-gon is .
Regular octagon
All sides of a regular octagon are the same length. Each corner is 135°. All corners added together equal 1080°.
Area
The amount of space a regular octagon takes up is
- [math]\displaystyle{ \text{Area} = 2(1+\sqrt{2})a^2. }[/math]
a is the length of one of its sides.
Another way to write it is
- [math]\displaystyle{ \text{Area} = 2 a^2 (\sqrt{2} + 1). }[/math]
Gallery
This shape is called an octagram. It has one regular octagon in the middle.
The octagonal prism has 2 octagons in it: one on the top, and the other on the bottom.
A non-regular octagon
Making an octagon by folding paper
Octagon Media
The diagonals of the green quadrilateral are equal in length and at right angles to each other
Regular Octagon Inscribed in a Circle
Meccano octagon construction.
en:8-cube family graph in A7 en:Coxeter plane
8-gon rhombic dissection-size2
Isotoxal 8-gon rhombic dissection-size2
8-gon rhombic dissection2-size2
8-gon rhombic dissection3-size2
