Boyko Bantchev wrote: > 2008/12/10 John Randall <[EMAIL PROTECTED]>: >> 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. > > ABCD will still be concave if D is, e.g., on the opposite side of BC from > A.
My initial thought was not so good. I'll leave it to Henry and Boyko to sort it out. Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
