Before revision: Let S be a set of  points in the plane, CH be the convex hull of S, \wp(S) be the set of all simple polygons crossing S, \gamma_P be the maximum angle of polygon P \in \wp(S) and \theta =min_{P\in\wp(S)} \gamma_P.
After revision: Let S be a set of points in the plane, \wp(S) be the set of all simple polygons crossing S, \gamma_P be the maximum angle of polygon P \in \wp(S) and \theta =min_{P\in\wp(S)} \gamma_P.