Dodecagon

The amount of space a regular dodecagon takes up is

${\displaystyle {\begin{aligned}A&=3\cot \left({\frac {\pi }{12}}\right)a^{2}=3\left(2+{\sqrt {3}}\right)a^{2}\\&\approx 11{,}19615\,a^{2}.\end{aligned}}}$

The variable A represents the area, and the variable a represents the apothem.

The perimeter of a regular dodecagon is

${\displaystyle {\begin{aligned}P=12s\end{aligned}}}$

The variable P represents the perimeter, and the variable s represents one side.