Tangram: análise de uma ferramenta para compreensão dos cálculos de áreas de figuras planas para os docentes do ensino médio

Abstract

The Article is an approach in which geometry contents are put into practice with the help of Tangram in the classroom, which sought to address mathematics contents including playful-ness in theory, making the student perceive mathematics in a pleasurable and motivating. Tan-gram is a simple and easy-to-use tool that serves to help teach geometry topics in mathematics. There are several types of Tangram: among them, Circular Tangram; Tangram Heart; Oval Tangram; Triangular Tangram and square Tangram, which is a case study in this article. Appli-cations in high school in different teaching modalities were researched. This work was carried out through research on articles that were applied in the classroom by other authors and with this we see their considerations, their difficulties, and above all the ease of using this manipu-lative material for teaching geometry. With the help of Tangram we can address: perimeters, areas, barycenter, side, vertex, edges and location of angles, and various theorems such as Pythagoras theorem, Thales, cosine, sine and similarities of triangles and other concepts. The Tangram is formed by five triangles, a square and a parallelogram, originating from the de-composition of a square. Telling from the beginning, the legend and how to build a Tangram, and showing the projects that were carried out in high schools.