Euclid

Euclid is an ancient Greek mathematician, considered the father of geometry, who is best known for Elements, the treatise that laid the foundations of geometry and largely dominated the field until the early 19th century. Working in Alexandria around 300 BC, he also wrote Optics, an early text in that field, along with works on perspective, conic sections, and number theory. Little is known of his life, and most of what survives about him comes from writers centuries later.