Octagon
An octagon or 8-gon is a polygon that has exactly 8 sides.
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]