Hippocrates of Chios

Hippocrates of Chios (Ancient Greek: Ἱπποκράτης ὁ Χῖος; c. 470 – c. 421 BC) was an ancient Greek mathematician, geometer, and astronomer. Originally a merchant on the island of Chios, he moved to Athens after experiencing financial misfortune. There, he became a prominent mathematician, possibly influenced by Oenopides of Chios and Pythagorean thought. His most significant contribution to mathematics was his 'Elements', the first systematic geometry textbook, which laid the groundwork for Euclid's later work. He is also credited with being the first to prove an area equality between a curved shape and a polygonal shape, in his work on 'Hippocratic lunes' as part of the problem of squaring the circle. Although he did not solve the problem, his methods were pioneering. Hippocrates also tackled the problem of duplicating the cube and developed the technique of 'reduction' to solve mathematical problems. In astronomy, he proposed theories about comets and the Milky Way, though his ideas are not clearly preserved. He is believed to have originated the use of letters to denote geometric points and figures.