The subject of the article is usage of modern computer technologies through the example of interactive geometry environment Geogebra as an innovative technology of representing and studying of geometrical material which involves such didactical opportunities as vizualisation, simulation and dynamics. There is shown a classification of geometric similarity transformations of the plane, computer tools of interactive geometry environment GeoGebra which are used for realization of similarity transformations. It is illustrated an opportunity of usage of these represented tools while studying of concerns and properties of geometric transformations, theorem proving, solving of construction tasks.