You need to install ActiveX plug-in to be able to view this model.
The model illustrates the geometrical proof of the Pythagorean theorem.
Radio buttons "Change", "Demo" and "Build" allow selecting mode.
In the Change mode you can change a leg of the triangle. Pick up a vertex of a sharp angle (cursor changes its shape) and transform the triangle.
In the Demo mode the model demonstrates the geometrical proof of the Pythagorean theorem. Click the Run button and observe the proofing.
In the Build mode you may proof the theorem in the same manner as in the Demo mode. Move right-angle triangles using the drag and drop technique, rearrange triangles in the square and proof the theorem.
You can download it here.