Polygon with sixteen sides.

- It has 104 diagonals.
- The sum of its interior angles is 2520°.
- If the hexadecagon is a regular hexadecagon, each of its interior angles measures 157.5 °.

### 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:

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

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

### Example

This is a regular hexadecagon in which interior angle measures are expressed as mixed numbers: