2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/68553A generalized hyperbolic tetrahedra is a polyhedron (possibly non-compact) with finite volume in hyperbolic space, obtained from a tetrahedron by the polar truncation at the vertices lying outside the space. In this paper it is proved that a volume formula for ordinary hyperbolic tetrahedra devised by J. Murakami and M. Yano can be applied to such ones. There are two key tools for the proof; one is so-called Schlafli's differential formula for hyperbolic polyhedra, and the other is a necessary and sufficient condition for given numbers to be the dihedral angles of a generalized hyperbolic simplex with respect to their dihedral angles.18 pages, 4 figures, minor errors corrected and two references are added. To appear in "Non-Euclidean Geometries, Ja'nos Bolyai memorial volume ...", by Kluwer Academic PressGeometric TopologyMetric Geometry52A38 (Primary) 51M09 (Secondary)text