bordier@imag.fr (Jerome Bordier) (03/19/91)
Cabri-geometre demonstration program is now avalaible. Cabri-geometre files should be retrieved from RASCAL RASCAL.ICS.UTEXAS.EDU has the IP-address 128.83.138.20 Cabri-geometre files are in directory mac/educational and are named Cabri-geometreDemo3L.sit.Bin Cabri-geometreDemoE.sit.Bin Cabri-geometre_README N.B. DemoE archive contains the English version. Demo3L archive contains the tri-lingual version (English-French-German). Language can be chosen in the "Preferences..." article of the "Edit" menu. For EUROPE, get files from IMAG IMAG.IMAG.FR has the IP-address 129.88.32.1 Cabri-geometre files are in directory pub/CABRI --------------------------CABRI-GEOMETRE INTRODUCTION---------------------- CABRI-GEOMETRE Cabri-geometre is a software which has been developed to be an help for teaching and learning elementary geometry. It allows you to draw on the screen most figures of Euclidian geometry, involving traditional geometrical objects as points, lines, line-segments, circles,... and geometrical relations like parallelism, orthogonality, reflection, equidistance,.... The investigation of the figure is then possible through a set of tools allowing dynamic modifications, measurements, graphical enhancements, property checking, ... The most impressive feature is the ability for the user to transform a given figure by moving (dragging) around the screen one or the other of its components The whole figure is continuously redrawn, keeping the rules of construction . In elementary geometry many assumptions are made only by looking at the aspect of a figure and on a classical notebook you are limited by the rigidity of your figure. With Cabri-geometre you can study or ignore peculiar cases and you can visualize as many instances of the class of figures you are studying as you like.The hypothesis you may have now about the properties of this class of figures become independent of the instance you have on the screen. Thus Cabri-geometre presents an alternative to the classical tools (such as paper, pencil, ruler, compasses,...) for constructing figures, investigating this figure in order to find new properties as well as for achieving new states of knowledge. Cabri-geometre may also be used as a tool to build simulations of phenomena in domains that can be interpreted by geometrical relations such as optics, algebra, ... The project CABRI (which stands for Cahier de Brouillon Informatique, i.e. computerized notebook) is developed at the Laboratoire de Structures Discretes et de Didactique (IMAG), a computer science and didactic team of the French Universite Joseph Fourier in Grenoble and is supported by the C.N.R.S. (Centre National de la Recherche Scientifique). Cabri-geometre has been rewarded with the French APPLE TROPHY 88 as the best realization for education. Cabri-geometre is available for Macintosh and IBM/PC compatible micro-computers. MAIN FEATURES - Self-contained (no Logo or other language) and easy to use. It can be immediately used by pupils of all ages. - Direct manipulation: you choose an item in the menus then point to the objects to be involved in the operation. - Dynamic accounting of geometrical relations between objects. - Real time redrawing of the figure when moving (dragging) around the screen one of the basic elements. - Visualization of loci of points: you can see the trace of one or many points when you drag any basic element (this is especially useful when the base element has the property to remain on a line or on a circle). - Extensibility through libraries of macro-constructions (composition of several basic constructions such as the circumscribed circle of a triangle), defined by the user and added to the Construction menu. These macros may be saved on the disk to be used in other sessions. - Adaptability of the items actually appearing in the menus, with respect to the knowledge state of the user. - Recording (and fast post-reading) of the different states of the figure during a pupil's session. - Measuring and calculating (lengthes, areas, slopes, ...) - Validation of properties (parallelism, alignment, equal lengthes, ...) in a general position. - Online help, simple and of easy access. - Over sixty explanatory messages guiding the user in case of wrong manipulation. FOR MORE INFORMATION Laboratoire de Structures Discretes et de Didactique (IMAG) projet "Cabri-geometre" BP 53X 38041 Grenoble FRANCE email : lsd@imag.fr -------------------------END OF CABRI-GEOMETRE INTRODUCTION --------------