There's an excellent program called 'Geogebra' (google it). It takes about a minute to reconstruct the pirate problem; see file here: http://ubuntuone.com/37Y5U

There's an excellent program called 'Geogebra' (google it). It takes about a minute to reconstruct the pirate problem; see file here: http://ubuntuone.com/37Y5UbvN6wqbYOWYPcict2 http://ubuntuone.com/37Y5UbvN6wqbYOWYPcict2, you can move around the point of the grave and see how the point of the treasure reacts (or doesn't)