Four pins are randomly nailed to a square board (according to a uniform probability distribution), and a rubber band is stretched completely around them to form a convex shape. What is the probability that the rubber band is in the shape of a triangle?

3 out of 4 would be my answer (or 0.75). I accept that you could make an endless number of 4 - sided polygons, but cannot fit this into the equation.

Posted by Angela on 2005-02-15 11:43:23