Formula

The formula to calculate the area A of a regular polygon with n sides, a radius of r and a central angle of α is:

[latex]A=n\times \sin\left(\frac{a}{2}\right)\times \sqrt{r^{2}-\left(\sin\left(\frac{a}{2}\right)\right )^{2}}[/latex].

In the case of a regular hexadecagon, if the radius is 1 cm, then the area is approximately [latex]3.18\textrm{cm}^{2}[/latex].