Exercising the model-view-controller pattern. The work is about creating a graphical view (another view beside the textual view) for the right triangle model. The graphical view displays the same change as the textual view when a change is made to the model through the textual view. You may use the same controller for the graphical view as the textual view or create another one dedicated to the graphical view (which is typical). Note that the user does not directly interact with the graphical view. It is just for displaying the change made through the textual view.