Picking r people out of n people sitting in a circle such that no two are adjacent = (n-r+1)Cr - (n-r-1)C(r-2) Picking r people out of n people sitting in a row such that no two are adjacent = (n - r + 1)Cr

Let A be the point at which the goat is tied. Now the radius of the circle is 21 So Total area of the circle will be pie r^2 = pie * 21 *21 But it covered 3/4 th of the circle + Some extra part So it will be 3/4 (pie * 21^2) + Red part + Yellow part = 3/4( pie * 21^2) + 1/4(pie * 14^2) + 1/4(pie * 7^2) = 1232 OA = A