Horn angle

In mathematics, a horn angle, also called a cornicular angle, is a type of curvilinear angle defined as the angle formed between a circle and a straight line tangent to it, or, more generally, the angle formed between two curves at a point where they are tangent to each other.

See also

• Angle
• History of geometry
• Non-Archimedean geometry

References

• Thomas Little Heath, T.L. (1908). The thirteen books of Euclid's Elements. 2. The University Press. pp. 39–42. 

External links

• Weisstein, Eric W.. "Horn Angle". http://mathworld.wolfram.com/HornAngle.html. 
• David E. Joyce, "Definition 8" Euclid's Elements Book I