A suggested activity using the nautical ring for the study of geometry

Abstract

This article presents an excerpt from an undergraduate research project that is still in progress, which seeks to develop an interface between History and Mathematics Teaching. Here, in the articulation between these two areas, we seek to study the Nautical Ring, with the intention of using this ancient historical mathematical instrument in didactic situations in the classroom in the future. The aim of this study is to present, using the Nautical Ring, a didactic situation aimed at teaching Geometry in Basic Education. To this end, we will first provide some information about the work in which the Nautical Ring is described, about the instrument itself and about the author who proposed it. Next, we talk about elements related to the construction of the Nautical Ring and, finally, we talk about the didactic sequence for teaching Geometry. During all these moments of the study, we used a qualitative research approach, and in the specific case of the didactic situation, we also used the Basic Unit of Problematization (BUP). The results show that working with the instrument can help teach some geometric concepts, such as the circle and the angle. As the person using the instrument mobilizes the concept of angle, they can see the relationship with the circumference, as this is evident when it is possible to conclude that the angle near the center is double that on the circumference. In view of what has been observed, we conclude that working with the Nautical Ring in the classroom can, in fact, promote the teaching of Geometry.