What is the maximum number of points in the Euclidean plane with the property that given any three points, at least two are at distance one apart?

(In reply to Bryan's solution by Bryan)

Wow.  That's surprisng.  You wouldn't think that such a simple question would be solved with this rather odd-looking figure.  I rated this problem a 5.  Nice work, Bryan.

Posted by Ken Haley on 2005-05-24 05:45:52