Resumen

Finding ways to improve geometry learning with dynamic geometric environment with touchscreen (DGEwT) is a new challenge in mathematics education. In this paper we illustrate some strategies concerning plane transformation used by two students to solve tasks on GeoGebra App and on Geometric Constructer (GC). Data came from videotapes of students working on the software, written answers for each task, the use of one shift in which he or she could write down and describe the function of each device icon, and from recorder SCR PRO. Two analytical protocols are presented. The proposed task and the possibilities of interaction provided by each device were fruitful to make emerge concepts related with plane transformation and to help students to solve the task by making spontaneous composition between them in a non-linear reasoning. Symmetry based on mirroring ideas took place in students’ strategy as a scaffolding concept during their interaction.