A Triacontahedron is made of 30 equal rhombuses - exactly like a D30 dice. Here is a flat Zometool model of its shadow, viewed along its 3-fold symmetry axis. To cast the shadow, insert a yellow (triangular) strut in any ball in the 3D triacontahedron model, and point it at a plane light source (like the sun). The screen on which the shadow is projected should be perpendicular to the light rays.