Heron

Heron (or Hero) of Alexandria (first century B.C.) is best known for having discovered the formula for calculating the area of a triangle. In Heron's formula, as it is called, the sides of a triangle are labeled "a," "b," and "c"; V is equal to half the perimeter.
Arab scholars who studied the mathematics of the ancient Greeks claimed that this formula was known earlier to Greek mathematician Archimedes (ca. 287-212 B.C). The oldest written record of the formula, however, exists in Heron's Metrica.