# Heptagon Calculator

A polygon with 7 vertices is called a heptagon, this calculator calculates the correct heptagon. This form is quite rare. Enter one known value, then click calculate.

**Heptagon calculator, enter one known value**

**Side length (a)**

**Large diagonal (d1)**

**Smaller diagonal (d2)**

**Height (h)**

**Perimeter (p)**

**Square (S)**

**The radius of the circumscribed circle (R)**

**Radius of the inscribed circle (r)**

## Formulas:

d = a / ( 2 * sin ( π/2 / 7 ) )

e = 2 * a * cos ( π / 7 )

h = a / ( 2 * tan ( π/2 / 7 ) )

p = 7 * a

S = 7/4 * a² / tan ( π / 7 )

R = a / ( 2 * sin ( π / 7 ) )

r = a / ( 2 * tan ( π / 7 ) )

Angle: 5/7*180° ≈ 128,57°, 14 diagonals.