Almada Negreiros and the Geometric Canon Sim˜ao Palmeirim Costa CIEBA, Centro de Investiga¸ c˜ ao e de Estudos em Belas-Artes, Faculdade de Belas Artes da Universidade de Lisboa simaopalmeirim@gmail.com Pedro J. Freitas Centro de Estruturas Lineares e Combinat´orias Faculdade de Ciˆ encias da Universidade de Lisboa pjfreitas@fc.ul.pt January 30, 2015 Abstract This paper presents a mathematical analysis of a series of geomet- rical abstract artworks by Portuguese author Almada Negreiros (1893- 1970), understood in the context of the author’s search for a canon. After a brief description of Almada’s work in the frame of 20th century visual arts, we examine the mathematical elements in three of his works: illustrations for a newspaper interview, two drawings from a collection called Language of the Square and his last visual work, the mural Come¸ car. The analysis revealed that some of the author’s geometrical con- structions were mathematically exact whereas others were approxima- tions. We used computer based drawings, along with mathematical de- ductions to examine the constructions presented in the aforementioned works, which we believe to be representative of Almada’s geometric statements. Our findings show that, albeit limited by the self-taught nature of his endeavor, the mathematical content of these artworks is surprisingly rich. The paper is meant to be an introduction to Almada’s work from a mathematical point of view, showing the importance of a compre- hensive study of the mathematical elements in the author’s body of work. 1