#### Answer

Between 49 and 77

#### Work Step by Step

We find the area of the circle:
$ A = \pi r^2 = \pi(3.5\sqrt{2})^2 \approx 77$
We find the area of the square. Since each triangle formed is a 45-45-90 triangle, we obtain that if the diagonal has length $3.5\sqrt2$, the sides must have length 7. Thus:
$A = 7^2 = 49$