THE SCHOOL OF ATHENS: Focus on Euclid

Euclid (here featured with a compass doing a proof) studied in Athens under the students of Plato sometime around 300 B.C.  We do not know his exact dates.  He later opened a school of mathematics and taught at the Library of Alexandria (Greece).  He is best known for his book The Elements, in which he uses only five postulates, five common notions, and twenty-three definitions to prove a large number of theorems in plane geometry.  He even managed an elegant proof of the Pythagorean Theorem.