In this project, our goal is to teach children both recycling and geometry through an integrated process, by constructing deltahedra from recycled plastic bottles. We demonstrate that the two-bottle modules can potentially represent all possible 2-manifold meshes. Moreover, for structural stability, we use triangular faces. All possible deltahedra; i.e., polyhedra whose faces are all equilateral triangles, can be constructed by assembling these two-bottle modular units. And, since we want the process to be as “easy and safe” as possible for children, we avoid cutting the bottles, and join them using common schoolroom materials: tape, rubber bands, etc.