the conic sections
, or two-dimensional figures formed by the intersection of a plane with a cone at different angles. the theory of these figures was developed extensively by the ancient greek mathematicians, surviving especially in works such as those of apollonius of perga. the conic sections pervade modern mathematics.
apollonius of perga (greek: Ἀπολλώνιος ὁ Περγαῖος; latin: apollonius pergaeus; late 3rd – early 2nd centuries bc) was a greek geometer and astronomer known for his theories on the topic of conic sections. beginning from the theories of euclid and archimedes on the topic, he brought them to the state they were in just before the invention of analytic geometry. his definitions of the terms ellipse, parabola, and hyperbola are the ones in use today.
apollonius worked on many other topics, including astronomy. most of the work has not survived except in fragmentary references in other authors. his hypothesis of eccentric orbits to explain the apparently aberrant motion of the planets, commonly believed until the middle ages, was superseded during the renaissance.