Geometric combinatorics is related to convex and discrete geometry, in particular polyhedral combinatorics. Every topological surface is homeomorphic to a polyhedral surface such that all facets are triangles. One can make a polyhedral Voronoi diagram mesh by dualizing a Delaunay triangulation simplicial mesh. Many traditional polyhedral forms are polyhedra in this sense. In some areas of mathematics, such as polyhedral combinatorics, a polytope is by definition convex. A uniform honeycomb in hyperbolic space is a uniform tessellation of uniform polyhedral cells. Research in polyhedral combinatorics falls into two distinct areas. The smallest pair of polyhedral cospectral mates are enneahedra with eight vertices each. In a cranked or polyhedral wing the dihedral angle varies along the span. Multiobjective linear programming is equivalent to polyhedral projection. Jr. Hoffman worked on the molecular orbital theory of polyhedral molecules. The tumors are made up of large, polyhedral, pleomorphic chromaffin cells. Brown fat cells or plurivacuolar cells are polyhedral in shape. There are many results on computing shortest paths which stays on a polyhedral surface. This layer is composed of polyhedral keratinocytes.