Munson, J. H. (1971). Efficient Calculations on Points and lines in the Euclidean Plane. Artificial Intelligence Group.
Calculations involving points and lines in Euclidean spaces are often subject to annoying anomalies when the trigonometric functions are invoked. This paper illustrates a method by which use of these functions may often be avoided, and presents explicit formulas for four basic calculations involving points and lines in two dimensions.