Regular Polygon

A polygon with all sides congruent and all angles congruent.

Measure of each interior angle: $\frac{(n - 2) \times 180°}{n}$

Exterior Angle Sum

The sum of exterior angles (one at each vertex) of ANY polygon is always $360°$.

$\text{Sum of exterior angles} = 360°$

Regular Polygon Exterior Angle

For a regular polygon: $\text{Each exterior angle} = \frac{360°}{n}$

Finding Number of Sides

If you know the interior angle measure of a regular polygon: $n = \frac{360°}{180° - \text{interior angle}}$

$= (8 - 2) \times 180°$ $= 6 \times 180°$ $= 1080°$

Answer: $1080°$