Computer aided learning of proving in school geometry

Dynamic Geometry Systems (DGS) are powerful presentation and visualisation tools; however, they are not so useful in helping students to prove facts and to understand how theorems and proofs originate in one's mind. To facilitate the learning of proving geometry facts a software program has been developed by the author. The considered geometric configuration is first constructed on a DGS. The programme reads the drawing and lists several 'observable' properties of the configuration. The student then sets the problem space by selecting the facts s/he finds relevant to the proof. Finally, the student builds a proof by connecting the facts in problem space with logical argumentations in an iconic and/or symbolic view. The software can be used as well for exploring configurations and finding out novel properties (theorems). The effect of using the software has been investigated on a small scale experiment.