This simple program should do the following: the user clicks 4 times on the panel. After every click a line should appear. After 4 clicks a polygon is on the panel. There should be 1 button on the panel which allows to select 1 of the 4 displayed lines. After line selection that line should be the reference to create a rectangle. Selected line should not be moved. The other 3 lines have to be repositioned in order to display a rectangle with 90 degree angles.