I'm a club polyhedra with students from sixth and fifth. The objective
is to construct and study the properties of Platonic solids, and all the resulting polyhedra (truncated, stars), before finding may be the most complicated.
What is very rich in this regard is the multiplicity of means of construction, for all budgets.
magnetized rods
With magnetic rods and metal balls (geomag style), we can quickly build the Platonic solids (the cube is a bit unstable, the icosahedron is nonsense).
Count 10 euros for a box.
Benefits: hands and quick construction. ideal for discovery of solids.
Disadvantages: The object can not be kept.
Patterns
By making patterns on a sheet of heavy paper (photocopy first equilateral triangle mesh), we get a good exercise vision in space.
Take an 8 or 20, and ask students to reconstruct the boss S'ad numbers of faces.
For the dodecahedron, we can trace the request of pentagons.
Advantages: inexpensive, an interesting exercise
Disadvantages: small objects are obtained.
Pieces to pick
is cut all the faces (triangles, squares, pentagons, hexagons), and they all glue together with tape. Provide several colors. For solids
truncated, you can leave blank the truncated part.
Advantages: provides coloring problems with adjacent faces of different colors
Disadvantages: The finish is not very nice, with lots of scotch standing.
Parts Built into each other
With equilateral triangles with a slit, one can get a nice 3D puzzle to get Tetraeder, octahedra and truncated icosahedron. With colored pieces, can also pose problems of color.
Advantage: object and removable
pretty Disadvantages: can not do that with these three solids.
Stems and pitons
When cutting pins and pin at each end by screwing a screw stud, you get an edge.
They are fixed together with string or collars (plastic wire used in plumbing or electricity).
Advantages: A solid object (the cube and the icosahedron, provide for corners). Once the object is achieved, we can make construction on the edges (by marking each edge the third, then the relaint can be obtained truncation. By marking the midpoints of the edges can be obtained with strings centers of the faces, then the dual solid)
Disadvantages: AC comes up quite expensive, and it's quite long to achieve.
toothpick
Ideal for cocktails.
Use cherry tomatoes to the vertices, edges for toothpicks.
Otherwise, we must find something strong enough to hold the rods in the right position and soft enough to be stung. I saw someone who was taking candy Valda. The blutak gives rather poor results over time.
Advantages: fast and fun
Disadvantages: small and not very pretty.
modular origami folding modular
involves making identical modules that are nested within each other. In seeking instructions, I realized that on Youtube, there are many films of folders that show all stages of folding.
Advantages: very nice, you can play with the colors of edges or faces
Disadvantages: quite tedious. The assembly is not always obvious. But it's worth it.
straw, twine and skewers peak
Cut straws 5 cm. Thread twine and bind to form the polyhedra.
It begs the question: can we obtain a polyhedron with seulles string? (Yes for the octahedron, not for others) and discuss the theory of graphs.
Once the polyhedron obtained, we can insert skewers into the straw. Relaint obtained by the stars. By connecting the tops of the stars, we get another polyhedron.
Advantages: cheap and quite impressive.
Disadvantages: quite tedious.
polyhedron obtained by braiding
