Heron's formula, named after the ancient Greek mathematician Hero of Alexandria, is a method used to calculate the area of a triangle when the lengths of all three sides are known. It is particularly useful when you do not know the height of the triangle or cannot easily calculate it. The formula is as follows: Let � a, � b, and � c be the lengths of the sides of a triangle. The semi-perimeter of the triangle, denoted as � s, is calculated as: � = � + � + � 2 s= 2 a+b+c ​ And then, the area � A of the triangle is given by: � = � ( � − � ) ( � − � ) ( � − � ) A= s(s−a)(s−b)(s−c) ​