What is one thing about these squares that is special?

The answer: the area of the small square + the area of the medium square = the area of the large square. This is because of the Pythagorean Theorem. The Pythagorean Theorem states that a^2 + b^2 = c^2 . (^2 = squared) To find the hypotenuse (C) of  triangle, multiply the area of a and b, then you square the area to get the side length of the hypotenuse. For example, 9+16 = 25. The square root of 25 is 5, maling the side length 5.