Heron's Formula

Heron's formula is used to calculate the area A of a triangle where the lengths of all three sides are given.

Rules:

First calculate s: s=\frac{1}{2}(a+b+c)

The area of the triangle is: A=\sqrt{s(s-a)(s-b)(s-c)}

Note: Heron's formula is not used when the height of the triangle is known - too much work!