Visual argumentations in teaching trigonometry

In this paper, we study the possibility of building a learning path that allows students to develop trigonometric knowledge and skills by the end of Grade 10 of secondary science-based schools. In particular, we describe an action research experiment, in part done through distance learning, aimed at incorporating all trigonometry topics within the framework of the study of Euclidean geometry. The inquiry-based learning methodology and the support of dynamic geometry software with a laboratory teaching approach were used. The learning path is based on several “visual/dynamic proof” and is explained by an example lesson on the Cosines Law. The experiment could be extended by teachers into physical/virtual classrooms and could offer practical strategies and tools for teaching trigonometry.