AN ELEMENTARY PROOF OF SFORZA-SANTALÓ RELATION FOR SPHERICAL AND HYPERBOLIC POLYHEDRA Cho, Yunhi;
We defined and studied a naturally extended hyperbolic space (see  and ). In this study, we describe Sforza's formula  and Santal's formula , which were rediscovered and later discussed by many mathematicians (Milnor , Surez-Peir , J. Murakami and Ushijima , and Mednykh ) in the spherical space in an elementary way. Thereafter, using the extended hyperbolic space, we apply the same method to prove their results in the hyperbolic space.
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