Find a way to cut a 4 by 4 square into only two pieces, then rejoin the two pieces to make an L shape 6 units high.
Twice as Big?
Age 7 to 11 Challenge Level
Try putting one shape in at a time, being careful not to leave any gaps which you won't be able to fill.
If you're not using the interactivity, you might like to use this sheet and cut out the smaller shapes.