We explore non euclidian geometry with 4
softwares such as 'Cabri2plus, Cabri3D, Geogebra
& Mathematica' interactively！. Which means you can manipulate figures
on files with mouse. You can download sourse
files or macros too.
I am a math teacher at a preparatory school in Tokyo and I love programing as well as geometry. I started this page for my fun and study. (you need pals to study something difficult, don't you think so?) There may be many mistakes because I am not a specialist. But there may be an advantage in it. Since I am not a specialist, I am not very concerned with abstract which is a requirement of modern mathmatics. And I am not very concerned with abstract itself. Thus this essay may have some readers. I will feel delighted if this happens.
One more thing. If you can read Japanese, you can read detailed explanation of each file and mathematical proves. To see the japanese version , please click here or the link in each chapter.