Please Help!! Lilly decides to include diagonals on all sides of a box and a three-dimensional diagonal through the center of the box. The diagonals across the front and back of the box are each 2 feet, the diagonals across the sides of the box are each 3 feet, and the diagonals across the top and bottom of the box are each 7 feet. How long is the diagonal through the center of the box?