Textbook: Computational Geometry: an Introduction, Springer-Verlag, 1993 (5th printing) by F.P. Preparata, and M.I. Shamos

Problem 3 in the textbook Preparata \& Shamos (p.148). Given a point p and a vertex v of a convex polygon P in the plane, give an algorithm to classify in constant time vertex v with respect to pv (as concave or supporting or reflex)