José de Almada Negreiros (1893-1970) is one of the most eminent representatives of Portuguese modernism in both literature and visual arts. From the 1940s, Almada started developing a taste for geometric abstraction, which invaded more and more his visual work. His last piece, a large mural called “Começar” (“To begin,” 1969) is the summit of this geometric quest: it contains only geometric constructions and annotations, with very little explanation to the public. In the past four years, the two authors of this article have studied Almada's geometric work extensively, making it possible to understand both content and intention of this monumental work. In this paper we present some of his own constructions for the golden angle, a geometric element very dear to Almada,which provide very good approximations to this angle.