Geogebra

Article excerpt

GEOGEBRA

http : //www. geogebra. org/cms/

Florida Atlantic University

777 Glades Road, Math Department

Boca Raton, FL 33431

561-297-2485

Free software

One of the more interesting educational aspects of the Internet today is that it can help support various communities of learners who freely share ideas and resources related to a specific educational focus. A particularly interesting community of learners is one centered around a piece of interactive mathematics software called GeoGebra. This software was developed by Markus Hohenwarter in 2001 at the University of Salsburg and is now supported by Florida Atlantic University. A large community of GeoGebra users now contributes instructional ideas and materials to the GeoGebra website using an Internet Wiki, which is a type of website interface that allows users to freely add and edit webpage content. The GeoGebra software itself is a blend of basic geometry, algebra, and calculus tools that are displayed within a dual graphics and text window. The software can be freely downloaded from the GeoGebra website and runs on a variety of platforms, including Windows, Macintosh, Linux, and Unix.

While GeoGebra has a fairly simple set of interactive mathematics tools focused primarily on geometric constructions, it addresses some relatively foundational topics in geometry and algebra. For example, basic constructions involving points, vectors, segments, lines, and conic sections are quite easy to do, as well as graphical illustrations on a variety of functions and functional notations. A dual view of mathematical objects is used, with expressions in the geometry window often corresponding directly to expressions in an algebra window (and vice versa). This GeoGebra dual window is relatively simple in its operations, and uses straightforward construction tools and menus.

Although the GeoGebra software is more basic than other packages that do geometric constructions (such as Geometer's Sketchpad), the price of the program is certainly appealing. As a freely downloadable and open source program, a user can download a single program for use at a workstation or download the program multiple times, such as within a computer laboratory. GeoGebra is partly supported by donations and product sales (such as GeoGebra shirts, hats, and buttons), with no doubt some ongoing help from Florida Atlantic University.

I was relatively impressed with GeoGebra's support materials (especially for a free program), including an extensive online help feature, a 42-page pdf help manual, downloadable "getting started" tutorials, and a variety of detailed lessons that use video-based step-by-step examples. These help features are all very concise, easy to access, and professionally done, with additional suggestions contributed by users. The GeoGebra website describes this collaborative help environment as focusing on "quality versus quantity", and that philosophy appears to be well reflected in this dynamic help environment. …