2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/216014We exhibit an algorithm to compute a Dirichlet domain for a cofinite Fuchsian group Gamma. As a consequence, we compute the invariants of Gamma, including an explicit finite presentation for Gamma.18 pages, uses pstricks; corrections made as suggested by referreeNumber Theory11F06; 20H10; 11R52text