The Law of Cosines
- Irina Boyadzhiev
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. Use the GeoGebra applet below to demonstrate the Law of Cosines: .
- Show the Cuoco's theorem by clicking on the checkbox.
- Drag the slider to rearrange the square with area .
- Click on the Right triangle checkbox to see this.