Read also the newer post: ThinkGeek’s Preposterous Puzzle Solved?
Many of you have already seen the lateral thinking puzzle commonly known as the missing square puzzle. It seems at first to be a paradox but it has a simple (yet far from obvious) solution. The first figure below seems to have a larger surface than the second since the second one is missing a square. However they are both formed by the same set of pieces. Can you explain what’s going on?
The Missing Square Puzzle
Once you have solved (or seen the solution to) this puzzle, you may wish to check out ThinkGeek’s real life variation of the missing square puzzle, the Prepousterous Puzzle.
The Hourly Puzzle 