Learning is the outcome of an activity and it is also developed via activity. Among activities which pupils perform quite often are mathematical games. If such games are performed according to the rules satisfying certain didactical goals, they are called didactical games in the educational process. These didactical games include various geometrical puzzles, among them an old Chinese puzzle called Tangram. From the educational point of view, Tangram assists in teaching geometry via developing:
1. geometrical knowledge,
2. reasoning,
3. geometrical imagination.
Geometrical imagination is ability to sense:
· geometrical shapes,
· their size and position in space,
· a given shape in different space positions,
· changes of shapes in their size, structure, etc.,
· a shape in space according to its plane projection and a word description,
· a plane representation of a given shape in space.