Hero's formula
[ heer-ohz ]
/ ˈhɪər oʊz /
noun Geometry.
the formula for the area of a triangle when the sides are given: for a triangle with sides a, b, and c, the area is equal to 
, where s is equal to one half the perimeter of the triangle.
, where s is equal to one half the perimeter of the triangle.
Origin of Hero's formula
named after
Hero of Alexandria