Director
A plane parallel to two (or more) skew lines, also called a director plane. The orientation of a director is fixed, but it is specified uniquely only if a point lying on it is also specified.
A director of two skew lines is perpendicular to the line of shortest distance of these two lines (Altshiller-Court 1979, p. 1).
See also
Skew LinesExplore with Wolfram|Alpha
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References
Altshiller-Court, N. Modern Pure Solid Geometry. New York: Chelsea, p. 1, 1979.Referenced on Wolfram|Alpha
DirectorCite this as:
Weisstein, Eric W. "Director." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Director.html