So let's try to find the part of it in one circle then multiply it by 2. if the vertical line of shaded reason is 4, then 2 would form a rt triangle with radius. thus the cos € = 2/4 = 1/2, so € = arccos (1/2) € = 60°, and 2× that = 120° so now one part of the shaded region is the whole sector (pi×r^2) - the triangle within (base×ht): [pi(4)^2×120/360] - [2(4cos30)] = [16pi×1/3] - [2×3.46] = 16.76 - 6.93 = 9.83 now double that for both parts of the shaded region: 9.83×2 = 19.65 sq. units