James ordered a fishing rod. Unfortunately, James is an Eskimo who lives in a very remote part of Greenland and the import rules there forbid any package longer than 4 feet to be imported.
The fishing rod is 4 feet and 1 inch, just a little too long, so how can the fishing rod be mailed to James without breaking the rules? The fishing rod has to arrive in one piece.
Answer
Use a square box that measures 4 feet on all sides. The fishing rod will fit the box when placed diagonally.
Based on Pythagorean theorem, the diagonal width of the box is √(42 + 42) = 5.6 feet.