Appendix 1:
Making the Round Wooden Ring
1. Prepare 3 pieces of wood exactly the same size: 420 mm x 140 mm x 70 mm
2. Join them together with glue.
3. Draw two circles on the wood, one with a radius of 200 mm and the other with a radius of 100 mm.
4. Cut out the ring with a compass or keyhole saw.
5. Shape the sides of the ring to obtain a slope as shown in the drawing.
