Build a 2-meter-wide circular road along the edge of a circular nursery with a radius of 20 meters. What is the area of this road in square meters?
在一个半径是20米的圆形苗圃边沿修一条2米宽的环行路．这条路面的面积是多少平方米？
<gadget id="calculator">20 + 2</gadget>
<output>22</output>

<gadget id="calculator">22 ** 2</gadget>
<output>484</output>

<gadget id="calculator">3.14 * 484</gadget>
<output>1_519.76</output>

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

<gadget id="calculator">3.14 * 400</gadget>
<output>1_256</output>

<gadget id="calculator">1_519.76 - 1_256</gadget>
<output>263.76</output>

<result>263.76</result>