The Area of the Disk in Middle School Grade by GeoGebra.

Abstract

The visualization and exploration of mathematical objects and concepts in multimedia environments can facilitate learning. Geometry is particularly involved with the growing use of software in teaching. GeoGebra is a dynamic geometry system that increases the level of knowledge and skills in mathematics. Use of GeoGebra permits to complete and extend a teaching strategy based on manipulative activities. The area of a disk in the Middle School, i.e. Grades 7-8 offers the opportunity to a large use of geometry dynamic software. This paper proposes, as example of combining between manipulative activating and dynamic geometry software, the use GeoGebra to permit the visualization of three different approaches to the area of a disk. First is based on the limit of the area of inscribed regular polygons, second on dynamical morphing of the disk in a triangle and third on sampling methods.