The dimension of the rectangle should be 3x14 cm and 14 cm. Thus, its area is 3x14 cm x 14 cm which is equal to 588 cm². The area of the 3 circles is,
3A = 3πr² = 3π(14 cm/2)² = 147π cm² = 461.81 cm²
The area of the shaded region is the difference between the areas which is equal to 126.19 cm².