A ruled surface 
is a normal developable of a curve 
if 
can be parameterized by 
, where 
is the normal vector (Gray
1993, pp. 352-354; first edition only).
Normal Developable
See also
Binormal Developable, Box-Muller Transformation, Tangent DevelopableExplore with Wolfram|Alpha
References
Gray, A. "Developables." §17.6 in Modern Differential Geometry of Curves and Surfaces. Boca Raton, FL: CRC Press, 1993.Referenced on Wolfram|Alpha
Normal DevelopableCite this as:
Weisstein, Eric W. "Normal Developable." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/NormalDevelopable.html