In this project learn a simple technique based on circles for making all five Platonic solids—tetrahedron, octahedron, icosahedron, cube, and dodecahedron. Each solid is made from a circle with the shape the solid is based on drawn inside of it. This construction technique reinforces the concepts of Platonic solids as the student assembles each solid.

Three dimensional objects with only flat (or plane) surfaces are known as polyhedra. There are many different polyhedra, but five of them have the property of being regular. A solid is regular if all planes (or faces) are the same, and the same number of planes meet at each corner (or vertex). Five solids qualify as regular (or Platonic) - three based on equilateral triangles (tetrahedron, octahedron, and icosahedron), one based on squares (cube), and one based on regular pentagons (dodecahedron).
For other geometric solids to make, see the project Geometric Solids.
Choose the platonic solid to make—there are templates for triangle, square and pentagon faces. For the cube print squares, for the dodecahedron print pentagons, and print triangles for the tetrahedron, the octahedron and the icosahedron (2 sheets). Download and print the pattern on paper or cardstock. The patterns are available in color or in black and white—to print on colored paper or ready for you to add your own design. There are also pentagon patterns for making dodecahedron calendars for 2011 and 2012.
Patterns are Adobe PDF files. The Adobe Reader is available for free.
All of Aunt Annie's project patterns are designed to be printed on standard letter size paper (8.5"x11" or A4). When printing from Adobe Reader you may need to select Auto-Rotate and Center or Choose paper source by PDF page size to ensure the best fit.
Cut on the outline of each circle.
Fold on each of the three (or four or five) fold lines. To hide the printed fold lines, turn the circle with the printed side down before folding; otherwise, keep the printed side up. Repeat for each circle. For circles printed on cardstock, score the fold lines first with the empty ballpoint pen.
You may optionally decorate the inner triangles, squares, or pentagons with crayons, markers, stickers, or rubberstamps. Decorate on the unprinted side.
When gluing, use the folded sides as glue tabs, and keep them on the outside.
Icosahedron only: Glue ten folded circles with triangles into a ring using the glue tabs.
Glue the parts together.
Icosahedron - Glue the top, to the ring, then glue the bottom to the ring.Tip: If you want, the glue tabs can be folded down and glued to a face or trimmed to one eighth inch.
Tip: Glue tabs can be glued inside for a neat look.
Tip: These solids can be used as gift boxes. Print directly on cardstock. Decide how you want the box to open and leave tabs unglued as needed for a lid.
Enlarge
Tip: The bottom halves of the dodecahedron and icosahedron
can be used as bowls for party decorations. Pictured is the bottom of
the dodecahedron filled with
paper flowers
attached to a balloon.