or Hero of Alexandria
flourished 0441; . AD 62, Alexandria, Egypt
Greek mathematician and inventor.
He is remembered for his formula for the area of a triangle and for inventing the aeolipile, the first steam engine , which, in his design, was a forerunner of the jet engine. Of his many treatises, one contains a method for approximating the square root of a number. His writings on mechanics include discussions of the five simple machine s, mechanical problems of daily life, and the construction of many kinds of engines.