Visual Proof Pythagorean Theorem

Move the sliders to adjust the lengths of "a" and "b". The large square has sides of length "a + b". The blue square inside the right diagram has sides of length "c".
1. Inside each large square: Is the total area of the blue (equal to, less than, or greater than) the total area of the lighter shaded regions. 2. How does the comparison of the two diagrams demonstrate the Pythagorean theorem?