Making Platonic Solids (3-D Shapes) With Straws and Pipe Cut all of your straws in half. To make the first shape, a triangular pyramid or a tetrahedron, you will need 6 straw halves and 3-4 pipe cleaners. Begin by making a triangle. Thread the pipe cleaner through three straw pieces. Twist them together at the top point. At each point of the triangle attach another straw 3D Shapes and Shapes out of Straws and Pipe Cleaners 3D Shapes and Shapes out of Straws and Pipe Cleaners. We made cubes, a rectangular prism, a triangular pyramid and a square pyramid. Corban just has fun sticking pipe cleaners in straws. It reminds me of one of his favorite activities with pipe cleaners. The link will take you to an idea that kept him entertained for quite a while on our plane trip to San Diego.