A knight comes to a castle where his love is trapped. The castle is surrounded by a square moat that is 10 feet wide (it forms a square around the castle). The knight is able to fashion two 9 foot long planks to cross the moat. How can he do this?
He puts one plank across the corner of the square (where two sides meet) and puts the other perpendicular to it to form a 'T' shape in the corner allowing him to cross the moat and save his beloved.