Quick answer
A nonagon is a polygon with 9 sides.
- Main formula
- Regular perimeter = 9 x side; regular area = (perimeter x apothem)/2.
- Quick example
- If each side measures 4, the perimeter is 36.
Definition
A nonagon is a closed polygon formed by 9 line segments.
Regular nonagon
In a regular nonagon, all sides and all interior angles are equal.
Formulas
- Perimeter of a regular nonagon: P = 9s.
- Area of a regular nonagon: A = (P x a)/2, where a is the apothem.
Example
If a regular nonagon has side length 4, then P = 9 x 4 = 36.