What is Heron's formula?
Heron's formula allows you to evaluate the area of a triangle knowing the length of its three sides.
For example; consider the triangle:
The area of this triangle is
Using Heron's formula:
The demonstration of Heron's formula can be found in textbooks of geometry or maths or in many websites. If you need it have a look at:
Area of a triangle with vertices
Oh yeah, Heron's Formula is