1. On the cardboard draw three equal squares (of 20cm each side). Cut them out with the cutter (you may need help of an adult!). Now you can write a number on the back side of each one of them (1-2-3).
2. On piece N.1, draw a smaller square of 15 x 15cm. The two squares should have the same centre and their sides should be parallel to one another.
3. Now cut this small square off, put it apart and use the remaining frame (N.1).
4. On piece N.2 repeat steps 2 and 3 and draw an even smaller square. For this one, draw sides of 11 cm long.
5. Cut this smaller square off and keep only the frame (N.2).
6. You are now ready to glue the pieces! Use the square piece of cardboard N.3 and place it in front of you. This will be the background. On this, first glue the frame N.2 and then, frame N.1. Be careful! Each external side of the three shapes should be aligned!
7.Now you have a blank coffer! You can design your own patterns on this, paint or decorate it with any extra materials you can find at home. Make many coffers and decorate the ceiling of your room, (as ancient Greeks did in their monumental buildings)!