Complementary function of the artifacts in the learning of geometric transformations with ninth graders

Abstract

This article presents several sequences of activities designed to promote the learning of geometric transformations, particularly dilation, and symmetry, refl ection, and translation (isometries). An exploratory study was conducted with 18 ninth grade students in a public school in Mexico, based on the exploration and manipulation of the dynamic geometry software, Cabri-II4, and a set of pantographs5 of diverse geometric confi gurations. Our main hypothesis relates to a complementary functionality important among the artifacts deployed. In particular, it is argued that specific utilization became useful to promote intuition and objectification of some mathematical notions at the end of basic education, such as proportionality and comparison between length and area.