The article Classifying solids using angle deficiency introduces the platonic solids. One is a cube. These shapes have been important to scientists and builders throughout history. The Egyptians used what they knew of these five shapes to help them design and build the Pyramids. Pyramids have a square base and most of them have four triangular sides, each of which are the same shape and size (or congruent).
See if you can build a cube from three pyramids. These pyramids are not regular because every side is not the same. | Image
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What you need:
- 3 pieces of card, better if they are different colours
- Pencil
- Ruler
- Scissors
- Sellotape
- Copy of the pyramid template below.
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What to do:
- Draw very carefully around the template on each piece of card. You could measure and draw the template yourself or you can copy the template onto the card if you have access to a photocopy or fax machine.
- Cut the shapes out, again taking care because the sides have to match up.
- Fold back the tabs along the dotted lines. To make the folding easier, have an adult help you score (cut part way) through the fold lines before you bend them back.
- Fold the triangles up so that the top, or apex, of them meet together,
- The tabs can be tucked inside the pyramid shape that you have formed.
- Put a small piece of selltape along the side to keep them neatly together.
- Do this for all three of the pyramid templates.
Your challenge:
Try to fit the three pyramids together to form a perfect cube. | Image
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Sound easy? You might be surprised to find it's not as easy as it seems.