Right conoid
Introduction A right conoid as a ruled surface.In geometry, a '''right conoid''' is a ruled surface generated by a family of straight lines that all intersect perpendicularly to a fixed straight line, called the ''axis'' of the right conoid.Using a Cartesian coordinate system in three-dimensional space, if we take the  to be the axis of a right conoid, then the right conoid can be represented by the parametric equations::::where  is some function for representing the ''height'' of the moving line.
Examples Generation of a typical right conoidA typical example of right conoids is given by the parametric equations: The image on the right shows how the coplanar lines generate the right conoid.Other right conoids include:*Helicoid: *Whitney umbrella: *Wallis's conical edge: *Plücker's conoid: *hyperbolic paraboloid:  (with x-axis and y-axis as its axes).
See also * Conoid* Helicoid* Whitney umbrella* Ruled surface
External links * *  Right Conoid from MathWorld. *  Plücker's conoid from MathWorld