We start with triangle ABC and construct a square on each side. The altitudes of the triangle extended to the opposite sides of the corresponding squares, cut each square in two rectangles.[br]Use the GeoGebra applet below to demonstrate the Law of Cosines: [math]c^2=a^2+b^2 – 2ab\; cos(\gamma)[/math].[br] Show Cuoco's theorem by clicking on the checkbox.[list][*]Drag the slider to rearrange the square with area [math]c^2[/math].[/*][/list]The Law of Cosines is a generalization of the Pythagorean theorem. [br] Click on the Right triangle checkbox to see this.[br]Drag the vertices of the triangle to see different configurations. [br][br][size=85]This applet is based on the article “[i]The Cuoco Configuration[/i]” by Roger E. Howe, The American Mathematical Monthly, Vol. 120, Dec. 2013, 916- 923.[/size]