Given:
A circle of radius r inscribed in a square.
To find:
The expression for the area of the shaded region.
Solution:
Area of a circle is:
Where, r is the radius of the circle.
Area of a square is:
Where, a is the side of the square.
A circle of radius r inscribed in a square. So, diameter of the circle is equal to the side of the square.
So, the area of the square is:
Now, the area of the shaded region is the difference between the area of the square and the area of the circle.
Therefore, the correct option is (a).