This work deals with analytical representation of congruent transforma- tion in a plane at high schools. The work is a web page, it contains several interactive components which help student to understand the problem like hyperlinks, stepping of the construction, applets, etc. The work contains several solved problems. Main emphasis is placed on the connection of the synthetic and the analytic approach to congruent transformation. The work uses knowledge of analytic geometry students learn at high school. The web page is aimed at talented students of high school and for teaching at mathematical class. 1