Repeat Square Puzzle

Description

This is a novel puzzle. You hand over four cut out green plastic pieces to a spectator to form into a perfect square. This is relatively easy, and the spectator will form the square with a few attempts. As an afterthought, you hand them  another piece – a small square. Now ask them to form a perfect square using all five pieces. This will prove much more difficult, until you demonstrate just how easy it really is.