  Given a set S of n points in the plane and a fixed angle 0 < omega < pi, we
show how to find in O(n log n) time all triangles of minimum area with one
angle omega that enclose S. We prove that in general, the solution cannot be
written without cubic roots. We also prove an Omega(n log n) lower bound for
this problem in the algebraic computation tree model. If the input is a convex
n-gon, our algorithm takes Theta(n) time.
