The formula for the area of a circle is A = πr^2
Since we know the length of the square is 7cm and the circle fills the full length, 7cm is the diameter.
To get the radius you divide the diameter by 2.
7/2 = 3.5
So, your radius is 3.5.
Now your formula looks like this: A = π(3.5)^2
Next you would square 3.5 because (3.5)^2 means to multiply 3.5 by 3.5
3.5^2 = 12.25
Now, you just multiply 12.25 by the approximate version of pi, which is 3.14.
12.25*3.14 = 38.465
Now, that you have the area of the circle, you subtract it from the area of the square.
If you already haven't figured out the area of the square it is 49 cm.
This is because the formula for the area of a square is A = bh or A = lw
Since the length (l) or base (b) is 7, we know that the other sides are 7 because squares have equal sides.
So now we subtract 38.465 from 49 and we get 10.535 which rounds to 10.54
So, your final answer is D. 10.54 cm^2
Hope this helps!