Math Playground
Geometry

Heron's formula proof

Why area = √(s(s−a)(s−b)(s−c)) — derived from Pythagoras.

Heron's formula gives the area of a triangle from its three sides — no height needed.

Drag the corners
161516
area ≈ 102.1 sq units
Heron's formula

Derived from Pythagoras and trig — but you don't need either to use it.