Raul Miller wrote: > What are the odds that any given quadrilateral is > not concave?
I think the answer will vary according to how big the quadrilaterals can be, and whether you are considering orientation. My initial thought is this: Draw the first 3 sides A->B->C. Let D be the other vertex. Then ABCD is convex iff D lies on the opposite side of the line AC from B. This gives probability at least 1/2 for your question. Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
