A brief review of GeoGebra: dynamic mathematics

There have always been two strands to elementary mathematics: algebra and geometry. Therefore it is perhaps not surprising that many computer packages have specifically targeted themselves at one strand. Computer algebra systems (CAS) are focused on manipulation of expressions and dynamic geometry packages concentrate on relationships between points lines circles and so on. Perhaps the best known examples of dynamic geometry are The Geometer’s Sketchpad (http://www.dynamicgeometry. com/) and Cabri Geometry. (Cabri also has a rather splendid three dimensional version Cabri3D and I have found version 2 invaluable for demonstrations in lectures.)