Our logo is a visual proof of Pythagoras' theorem, which states that in a right triangle, the square of the hypotenuse is equal to the sum of the squares of the two adjacent sides.
The right triangle in question is the blue triangle in the logo. The logo is divided into two equal squares (you can tell they are squares because each side has length equal to the sum of the two legs of the triangle).
In the left half, there are four copies of the right triangle, and a square on each of the legs. In the right half, there are also four copies of the right triangle and a square on the hypotenuse. Since the two halves of the logo have the same area, and all the right triangles have the same area, the two small squares on the legs must have the same total area as the square on the hypotenuse.
