With the green struts, which were introduced to the Zometool universe at a later date, you can now build accurate octahedra and tetrahedra. These struts end with pentagons and thus belong in the same opneings as the red struts. Since the endings of the green struts are bent slightly they fit into the pentagonal hole in five different ways and can generate five different directions.
This kit also enables you to build all 13 archimedean solids.
Green lines make Zometool more versatile and complex.
Green lines hijack the pentagonal (red) holes in the ball. But because of their design (double kinked) each strut can go into a hole in one of five different ways adding 30 new directions from each ball!
The most basic way to picture what the green lines do with a square. The green line is the diagonal line between corners.
Of course, this is just the beginning, Green lines open up a fascinating new world of building possibilities including truncations, ruled surfaces and some important basic shapes as well; for example, 2 of the platonic solids (tetrahedron and octahedron) can only be built properly with Green lines.