Polyhedron A polyhedron is a three dimensional region of space bounded by polygons.
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Faces The faces of a polyhedron are each of the two dimensional polygons that border the polyhedron.
Edges The edges of a polyhedron are the sides of the faces of the polyhedron. Two faces have an edge in common.
Vertices The vertices of a polyhedron are the vertices of each of the faces of the polyhedron. Three faces coincide with the same vertex.
Dihedral Angles The dihedral angles are formed between two faces of all neighboring polygons.
Polyhedral Angles Polyhedral angles are formed by three or more faces of the polyhedron and have a common vertex.
Diagonals The diagonals of a polyhedron are the line segments joining two vertices not belonging to the same face.
Euler's formula It is verified that in all convex polyhedra: No. of faces + No. of vertices = No. of de edges + 2.