Quick answer
A decagon is a polygon with 10 sides.
- Main formula
- Regular perimeter = 10 x side; regular area = (perimeter x apothem)/2.
- Quick example
- If each side measures 4, the perimeter is 40.
Definition
A decagon is a closed polygon formed by 10 line segments.
Regular decagon
In a regular decagon, all sides and all interior angles are equal.
Formulas
- Perimeter of a regular decagon: P = 10s.
- Area of a regular decagon: A = (P x a)/2, where a is the apothem.
Example
If a regular decagon has side length 4, then P = 10 x 4 = 40.