Sum of Polygon Angles

Given an n-sided regular polygon n, return the total sum of internal angles (in degrees).

Examples

sumPolygon(3) ➞ 180

sumPolygon(4) ➞ 360

sumPolygon(6) ➞ 720

Notes

• n will always be greater than 2.
• The formula (n - 2) x 180 gives the sum of all the measures of the angles of an n-sided polygon.