In this problem we are faced with an apparently easy area problem,
but it has gone horribly wrong! What happened?
Follow the instructions and you can take a rectangle, cut it into 4 pieces, discard two small triangles, put together the remaining two pieces and end up with a rectangle the same size. Try it!
You can move the 4 pieces of the jigsaw and fit them into both
outlines. Explain what has happened to the missing one unit of
This problem is taken from the UKMT Mathematical Challenges.