First find the area of the rectangle: 10 * 40 = 400
Now, since the square has the same area, we'll find the side lengths of the square by just finding the square root of 400 which is 20. You can do this with a calculator. So the side length of any side on the square is 20.
Paul must get 13 since Peter gets more more than Jane so Jane would get 7 and then peter would get 12