Apollonius of Perga at English => English (The Britannica Concise) Of Explained:
Anatolian mathematician known as "The Great Geometer." His Conics, one of the greatest scientific treatises of the ancient world, built on the work of Euclid. In it he introduced the terms parabola, ellipse, and hyperbola. He also improved on Archimedes' approximation of p. Much of his work is lost, known only through references in works of his followers.