When studying solid geometry, there is no substitute for holding a model in your hands, and this fun but challenging book offers that very opportunity. Twelve cut-and-assemble models of icosahedra offer children and professional mathematicians alike a tangible way to appreciate the structure and intrinsic beauty of polyhedra. The models range in difficulty from simple to complex. Some feature colors that reveal their relationships, and all five underlying shapes are rendered in white to emphasize their overall structure and to allow model-makers to color them as they wish. This hands-on educational activity book includes complete step-by-step instructions and diagrams for assembly plus mathematical explanations of the geometric shapes. Ideal classroom tools for teachers of high school and college geometry courses, these models are also charming diversions for papercraft hobbyists.