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).
Answer:
5 units
Step-by-step explanation:
The hypotenuse is always the longest segment on a triangle. If the lengths of the sides of this triangle are 3 units, 4 units, and 5 units, the hypotenuse will be 5 units. You can use the pythagorean theorem to check.
a^2+b^2=c^2
If you substitute the variable with the lengths of the legs in ascending order, you will get 3^2+4^2=5^2. Simplifying the equation, you will get 9+16=25, or 25=25. Thus, proving the equation.
Hope this helped! :)