Euclid

Euclid (Εύκλείδες, c. 300 BC) was a Greek mathematician. He worked in Alexandria at the Museum founded by Ptolemy I. He systematized the geometric and arithmetic knowledge of his times in thirteen Books—Euclid's elements (Στοιχεία).

Besides the Elements, Euclid wrote several other books. Of these Data, On Divisions of Figures, the Phaenomena, and the Optics have been passed to posterity. Data is a collection of 94 geometric propositions, On Division of Figures deals with problems of dividing a given figure by one or more straight lines, the Optics is the first Greek treatise on perspective, and the Phaenomena is an introduction to mathematical astronomy.

Nothing else is known of Euclid's life. That he lived and worked in Alexandria in the days of Ptolemy I is reported to us by the Greek philosopher Proclus (c. AD 410–485) in his "summary" of famous Greek mathematicians. Probably Euclid is older than Archimedes (c. 290/280–212/211 BC).