enneacontahedron

An enneacontahedron is a polyhedron with 90 faces. There are many possible shapes for an enneacontahedron, as the number of faces alone does not uniquely define a polyhedron. For example, an enneacontahedron could be a convex polyhedron or a non-convex one. The faces themselves can be of various shapes, such as triangles, quadrilaterals, or even more complex polygons.

One notable example of a polyhedron with 90 faces is the rhombic enneacontahedron, a Catalan solid. This particular shape is the dual of the uniform truncated icosidodecahedron. Its faces are all congruent rhombi. The rhombic enneacontahedron has 60 vertices and 120 edges. It can be classified as a convex polyhedron.

Another type of enneacontahedron might arise from modifications of existing polyhedra. For instance, if a polyhedron with fewer faces is subjected to a process that adds faces, it could result in an enneacontahedron. The specific arrangement and type of faces would depend on the method used. Therefore, "enneacontahedron" serves as a general classification based on the number of faces, rather than a singular, uniquely defined geometric object.