Question 1157966
The side of the square must be 16 units
That is the diameter of the circle.

The area of the circle is 8^2*pi or 64 pi square units or 201.1 square units.  The total area of the square is 256 sq units

The leftover is 54.9 sq units, 256-201.1

the circle takes up pi/4 of the square's area.