The plane through an edge of a trihedron drawn perpendicularly to the opposite face. The term was first used by J. Neuberg (Altshiller-Court 1979, p. 298).
Altitude Plane
Explore with Wolfram|Alpha
References
Altshiller-Court, N. Modern Pure Solid Geometry. New York: Chelsea, p. 27, 1979.Referenced on Wolfram|Alpha
Altitude PlaneCite this as:
Weisstein, Eric W. "Altitude Plane." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/AltitudePlane.html