# Regular Polygons

## Area of regular polygons

### 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)

PolygonNumber 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

## Related Topics

• Mathematics - Mathematical rules and laws - numbers, areas, volumes, exponents, trigonometric functions and more

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