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A conic section is the curve obtained by the intersection of a plane and a cone (a conic surface).

These are:

* circle - cutting perpendicular to the

* ellipse - cutting at an angle

* parabola - cutting

* hyperbola - cutting

| http://upload.wikimedia.org/wikipedia/commons/9/97/Conic_section_(PSF).png |

| |>> Image courtesy of the wiki commons. <<| |

There are some degenerate

* point - a degenerate circle (or ellipse)

* line - a degenerate parabola

* intersecting lines - a degenerate hyperbola