Home The first rigorous mathematical definition of a circle was given by Euclid (circa 300 BC) in his Elements (Definition 15). The first rigorous mathematical definition of a circle was given by Euclid (circa 300 BC) in his Elements (Definition 15). By -kekiuss February 15, 2026 0 The first rigorous mathematical definition of a circle was given by Euclid (circa 300 BC) in his Elements (Definition 15). Facebook Twitter Whatsapp Newer Older