Let E be the center of the large semi- circle
Note that the radius of this semi-circle is = 2
So AB = EA = EB = 2
So triangle AEB is equilateral and its area = (1/2) 2^2 * sqrt (3)/. 2 = sqrt (3) (A)
And the area between AB and the edge of the larger semi-circle = pi * 2^2 * 60 / 360 = (2/3)pi (B)
So....the white area of the small semicircle = B - A = (2/3)pi -sqrt (3)
And the radius of the small semi-circle = 1
So the area of the small semi-circle = (1/2) pi (1)^2 = pi /2
Shaded area = pi/2 - ( 2/3 pi -sqrt 3) = sqrt (3) - pi/6
