In the square ABCD, the side of the square is equal to the diameter of the circle.

We have been asked to the value of shaded region in terms of r.

The area of the square in terms of the diameter is \((2r)^2 = 4r^2\) since the diameter is twice the radius

Similarly, the area of the semicircle is \(\frac{1}{2}*π*r^2\)

The area of the shaded region is the difference between the area of the square and the area of semicircle,

which is \(4r^2 - \frac{1}{2}*π*r^2 = r^2(4 - π/2)\) (Option E)

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