Abstract
To meet the requirements of a highly information-driven society, the aims of mathematics education must change from merely teaching knowledge or technique to cultivating mathematical outlook or logical way of thinking. This holds true for geometry, which is one part of the current mathematics curriculum. To satisfy these requirements, we think that a learning environments for clarifying and correcting students' own ideas through practical and geometrical activities is needed, and that it can be realized by using computers and software tools designed for educationa purposes.
