Regular Polygons
Areas of regular polygons - polygons with 3 to 12 sides.

Perimeter of a Regular Polygon
P = n a (1)
where
P = perimeter (m, ft ..)
n = number of sides
a = length of side (m, ft, ..)
Area of a Regular Polygon
A = n a r / 2
= n r2 tan(Θ)
= n R2 sin(2 Θ) / 2 (2)
| Polygon | Number of Sides - n - | Area (m2, ft2..) |
|---|---|---|
| Triangle, equilateral | 3 | 0.4330 a2 |
| Square | 4 | 1.0000 a2 |
| Pentagon | 5 | 1.7205 a2 |
| Hexagon | 6 | 2.5981 a2 |
| Heptagon | 7 | 3.6339 a2 |
| Octagon | 8 | 4.8284 a2 |
| Nonagon | 9 | 6.1818 a2 |
| Decagon | 10 | 7.6942 a2 |
| Undecagon | 11 | 9.3656 a2 |
| Dodecagon | 12 | 11.1961 a2 |