Hero (or Heron) of Alexandria (Greek: Ἥρων ὁ Ἀλεξανδρεύς) (c. 10–70 AD) was an ancient Greek mathematician and engineer.[1][2] He lived and worked in Alexandria when Alexander the Great ruled. He is known for his inventions and experiments. One of his well known inventions was the Aeolipile (a simple steam turbine). He also discovered a way to calculate square roots, and Heron's formula for finding the area of a triangle.
Cajori says "Hero was a practical surveyor, so it is not surprising to find little resemblance between his writing and those of Euclid or Apollonius".[3][4]
At least from the days of Alexander the Great to the close of the classical world, there undoubtedly was much intercommunication between Greece and Mesopotamia, and it seems to be clear that the Babylonian arithmetic and algebraic formulas continued to exert considerable influence in the Hellenistic world. This aspect of mathematics, for example, appears so strongly in Heron of Alexandria (fl. ca. A.D. 100) that Heron once was thought to be Egyptian or Phoenician rather than Greek. Now it is thought that Heron portrays a type of mathematics that had long been present in Greece but does not find a representative among the great figures – except perhaps as portrayed by Ptolemy in the Tetrabiblos.