Hero of Alexandria

Hero (or Heron) of Alexandria () (c. 10–70 AD) was an ancient Greek mathematician and engineer. 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".