The configuration formed by two curves starting at a point, called the vertex 
, in a common direction. Horn angles
are concrete illustrations of non-Archimedean
geometries.
Horn Angle
See also
Non-Archimedean GeometryExplore with Wolfram|Alpha
References
Harrison, I. and Kasner, E. "Voltaire on Mathematics and the Horn Angle." Scripta Math. 16, 13-21, 1950.Kasner, E. "The Recent Theory of the Horn Angle." Scripta Math 11, 263-267, 1945.Referenced on Wolfram|Alpha
Horn AngleCite this as:
Weisstein, Eric W. "Horn Angle." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/HornAngle.html