This paper reports the analysis of the didactical management of two mathematics teachers in Chile, from direct observation of their geometry classes about the Pythagorean Theorem, in grade 7 and students 12 to 13 years old. The aim of the study is to detect in classroom management, indicators of teachers´didactical decisions about the topic and see if their efforts follow a didactic model of pedagogical action. This study focuses on the analysis of selected episodes of the lessons, which is part of a constructivist approach to learning and teaching of mathematics, based on key ideas of the theory of didactic situations of Brousseau. The management of both teachers leads to a transmission model of knowledge that hampers the development of mathematics and student protagonism.
Theory of Didactical Situations; Case Studies; Pythagorean Theorem; Didactic Management