The square is square so all sides are equal.

If we divide it horizontally, we have two smaller squares (left side) which are half shaded.

So we 50% shaded right and 1/2 of 50% shaded = 75%

Area of a circle = and r = 7 so the area of our circle is

The diagonal of the square is 2*7=14 and the sides are equal.

c is the diagonal so c =14.

Area of a square is a*a so we have 98 is the area.

Area of shaded region is

Now divide by total area.