An alternative approach to proof in dynamic geometry

MdeV shared this question 5 years ago

My 1998 paper "An alternative approach to proof in dynamic geometry", available at

might be of interest to several Geogebra users. It critiques the traditional approach to proof which focusses mainly on the verification function of proof, and argues for an alternative, more meaningful introduction (start) to proof, specifically in the context of dynamic geometry, by focussing on the explanatory function of proof in relation to interesting, surprising results. (25 pp, 5.3 MB, PDF).

Of interest too might be my 1999 paper "The role of proof with Sketchpad", which is available at:

This paper is a shortened version of my 1990 paper "The role and function of proof in mathematics", presents a case for developing understanding of different functions of proof within a dynamic geometry environment, e. explanation, discovery, verification, systemaization, intellectual challenge and communication.

Lastly my Dynamic Geometry sketches site at: contains Java applets with a variety of software ilcluding Geogebra, and includes a section on "Explorations for students". Several generalizations of famous theorems such as Napoleon, Viviani, nine-point circle, Van Aubel, etc. are also available for dynamic manipulation.

Comments (4)


Dear Michael, thank you for sharing your papers on proofs in dynamic geometry! We also focus on a similar approach like you introduced in your papers. The forthcoming version 5.0 will support theorem proving in such a way as well.

Some of your papers are already well known to us (including my colleagues). Here I refer to my web page where you can find slides for some former talks at We also plan to publish other papers concerning your framework and implementing a suitable environment in GeoGebra, too. Some preliminary applets can be seen at

Best regards, Zoltan


Great new for all users! Great works!


Dear Zoltan

Thanks for the welcome and all the useful URL's! The theorem proving feature for GeoGebra sounds really interesting as does the 3D beta version, which I've not yet looked at, but hope to do so soon.

I've also added/shared on the GeoGebraTube some links to GeoGebra pages I have on my Dynamic Geometry Sketches site, for example, here's one on "A general formula for the interior angle sum of polygons (including crossed ones)":

Have also added 3 others on a nine-point conic, Spieker conic and Nickal's theorem respectively.





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