A Ruled Surface is called a generalized cylinder if it can be parameterized by , where is a fixed point. A generalized cylinder is a Regular Surface wherever . The above surface is a generalized cylinder over a Cardioid. A generalized cylinder is a Flat Surface.

**References**

Gray, A. *Modern Differential Geometry of Curves and Surfaces.* Boca Raton, FL: CRC Press, pp. 341-342, 1993.

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1999-05-25