2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/228689We prove that the only self-similar surfaces of Euclidean 3-space which are foliated by circles are the self-similar surfaces of revolution discovered by S. Angenent and that the only ruled, self-similar surfaces are the cylinders over planar self-similar curves.11 pagesDifferential Geometry53C44Two non existence results for the self-similar equation in Euclidean 3-spacetext