Descriptores de los procesos de descripción, definición y demostración para los niveles de Van Hiele cuando se estudian las razones trigonométricas

This article presents some partial results of a research project conducted on 10th grade students from a school in Bucaramanga, Santander, in order to characterize Van Hiele reasoning levels that are specific to the processes of description, definition, and demonstration of trigonometric ratios. We first use a teaching unit of trigonometric ratios in a Dynamic Geometry System (DGS) and the Van Hiele model, which allowed us to analyze the evolution of students' reasoning. During the first stage of our study, we made an a priori characterization of the processes on each Van Hiele level, and we designed the teaching unit of trigonometric ratios. We show the descriptors for the first activity along with some examples of the students' actions before the proposed tasks.