Аннотация:
We consider hyperbolic octahedra with $mmm$-symmetry. We provide an existence theorem for them and establish trigonometrical identities involving lengths of edges and dihedral angles (the sine-tangent rules). Then we apply the Schläfli formula to find the volume of prescribed octahedra in terms of dihedral angles explicitly.
Ключевые слова:hyperbolic octahedron, $mmm$-symmetry, hyperbolic volume, existence theorem, sine-tangent rule.