%0 Journal Article %A Díaz Sánchez, Raquel %A Ushijima, Akira %T On the properness of some algebraic equations appearing in Fuchsian Groups %D 2009 %@ 0146-4124 %U https://hdl.handle.net/20.500.14352/50026 %X In this paper we give necessary and sufficient conditions on three orientation-preserving hyperbolic isometries T1,T2,T3 so that for any point x ∈ H2 the orthogonal bisectors of the three segments with endpoints x, Ti(x) intersect. This is equivalent to proving the properness of certain algebraic sets. As a corollary, we give a new proof for the existence and density of generic fundamental polygons for cocompact Fuchsian groups. %~