# Heron's Formula

Written by Jerry Ratzlaff on . Posted in Geometry

When given three sides of a triangle $$\; a,\ b, \ c$$.

The area $$\;A\;$$ of the triangle is given by:

### Perimeter formula

$$p = a+b+c$$

Semiperimeter: $$\; s \equiv \frac{1}{2} p$$

### Area formula

$$A= \sqrt { s(s-a)(s-b)(s-c) }$$

Semiperimeter: $$\; s \equiv \frac{1}{2} (a+b+c)$$