Find the area of the shaded regions below. Give your answer as a completely simplified exact value in terms of pi (no approximations). PLS need help - thanks :)

In 2014, the three largest economies in the world were (listed in order, from largest): a) the u.s., china, germany. b) the u.s., china, japan. c) china, the u.s., japan. d) china, the u.s., germany.