A square has all four corners on a circle of radius 14 cm…

Step 1. The circle. $\dfrac{22}{7} \times 14 \times 14 = 616\ \text{cm}^2$.

Step 2. The square. The diagonal is $28\ \text{cm}$, so the side is $14\sqrt{2}\ \text{cm}$ and the area is $2 \times 14^2 = 392\ \text{cm}^2$.

Step 3. The shaded part. $616 - 392 = 224\ \text{cm}^2$.