Here one idea for your consideration:
Students need to make the connectors. By connecting them they can build all
sorts of geometric 3-d forms in space. Connectors can be made by rolling
typing paper slightly smaller than crayons. Insert them with some white
glue. Tape until glue dries.
Children can cut cardboard tubes to any length very easily with any fine
toothed hand saw. If you know of a shop with a band saw, you can precut a
variety of lengths in a few minutes.
I might start with a very simple prescribed practice triangular form using
only 6 pieces of 4 inch tubing (a tetrahedron). Next, I would ask them to
play around to come up with an original piece with 10 to 15 segments.
Once they have played with the possibilities, you can ask them to design
original playground equipment and park shelters. This may a good chance to
have students learn to work in small groups.
Finished structures (3-D linear forms) can be painted.
The forms can be enclosed fully or partially with pieces of paper or pieces
of overhead transparency sheeting glued to the shapes to produce 3-D
planar-linear forms or closed planar forms.
Lastly, once your class has invented their own original forms they will be
absolutely fascinated by the work of R. Buchminister Fuller, the inventor of
the geodesic dome. It is a perfect lead in to art history. If you don't have
books or videos about him, try this search engine to find information.
"The Design Continuum" by Kranz and Fisher is a resource for 3-D design
theory of this type. It is probably out of print, but some libraries may