The first question is this: the smallest square is square A, and that is 9 units. and square E is two times that, and so on.
Square A's side length is 9 units and the area is 81.
Square E's side length is 18 and the area is 324.
Square C's side length is 27 and the area is 729.
Square B's side length is 36 and the area is 1,296.
Square D's side length is 45 and the area is 2,025