In mathematics, a conic section is a curve obtained as the intersection of the surface of a cone with a plane. The three types of conic section are the hyperbola, the parabola, and the ellipse; the circle is a special case of the ellipse, though historically it was sometimes called a fourth type.
Conic sections are formed on a plane when that plane slices through the edge of one or both of a pair of right circular cones stacked tip to tip.
