Triangle angle sums related to translation curves in Sol geometry

Source abstract

"After having investigated the geodesic and translation triangles and their angle sums in Nil and SL_2R geometries we consider the analogous problem in Sol space that is one of the eight 3-dimensional Thurston geometries. We analyse the interior angle sums of translation triangles in Sol geometry and prove that it can be larger or equal than pi . In our work we will use the projective model of Sol described by E. Molnar in [9]."