Question: 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?
Answer: 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.