How would you go about finding the area of the shaded region?
(Area of I + Area of III) + (Area of II + Area of IV)
We would find the area of unshaded region that are opposite to each other and by taking them in pairs.
Area of shaded regions, I +III = II+IV = Area of square - Area of 2 semicircles(which includes I and III as the shaded portions)
=side2−2×πr22
=side2−πr2