Which of the following dice is not a platonic solid?
Explanation
A platonic solid is a 3D shape that meets five criteria: it must be regular (all sides, angles, and faces are identical), all edges must meet at right angles, all vertices (corners) must be equal, and all facets (faces) must be polygons. The only platonic solids are the cube, dodecahedron, octahedron, tetrahedron, and icosahedron. A 10-sided die has ten sides, but its faces are irregular pentagons, making it impossible for it to be a platonic solid.