There is a circular fish pond in the park. The circumference of the fish pond is 125.6m. There is a circular island in the middle of the pond with a radius of 10m. How big is the water area of this fish pond?
公园里有一个圆形鱼池，量得鱼池的周长是125.6m，池的中间有一个圆形小岛，半径是10m．这个鱼池的水域面积有多大？
<gadget id="calculator">125.6 / 3.14 / 2</gadget>
<output>20</output>

<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">400 - 100</gadget>
<output>300</output>

<gadget id="calculator">3.14 * 300</gadget>
<output>942</output>

<result>942</result>