The mathematics incorporated in the construction of the quadrant described in the oeuvre Libros del Saber de Astronomía

Abstract

Among the various alternatives to insert the history of mathematics in the teaching, we see the mathematical instruments, in particular, the Quadrant in a quarter circle, or nautical Quadrant, used in position astronomy, as a resource that incorporates, manipulates and disseminates several concepts. This way, the article intends to show the mathematics present in the construction of the Quadrant in the search for interfaces that allow the articulation of mathematical concepts in the classroom. The construction of the Quadrant is based on the oeuvre Libros del saber de Astronomía: Libro del quadrante from the king D. Afonso X of Cartilha, written between 1276 and 1279. This instrument presents geometric properties that can be incorporated in mathematics classes, mainly, involving the geometric constructions, triangle similarity and fundamentals concepts of trigonometry. We consider that the didactic competence of the mathematical instrument for teaching is something tangible and possible to be introduced in the classroom. However, we must observe it as an element that aggregates knowledge, and not only the understanding of the mathematical relationships involved in its construction and use, but the understanding of the reasons of certain constructions to be carried out that way or why they are in that location.