Geometry is a branch of mathematics applicable to many areas. This explains the importance of developing geometric thought of scholars. The teacher plays a big role as he or she will contribute to this aspect of development by creating lessons and a series of activities intended for pupils. After introduction, the first chapter of this thesis describes Van Hiele model of geometric thought. First the theoretical approach and afterwards the congruent student activities related to specific levels of van Hiele geometrical thought. Second chapter defines numerous activities performed by using geoboards, which shows the efficiency of implementing didactic apparatus and specific materials in student's work and progress. By advancing the thought levels of geometric thought, pupils become more able to understand and thence produce a specific mathematical argument of a certain theorem. The tool of dynamic geometry can be of a great assistance, therefore the third chapter is dedicated to proving the argument and conducting student activities using some of the tools of dynamic geometry. Not infrequently scholars confront problems using some of the tools of dynamic geometry, especially proving theorems. The last, fourth chapter deals with describing the project whose goal was to determine the level of geometrical knowledge and the level of geometrical thought in which certain pupil is situated. Besides, one of the test instruments has reviewed the student's ability of understanding and independent proving of arguments.