An automatic sprinkler irrigation equipment with a range of 20 meters. This equipment rotates once, how many square meters is the area of sprinkler irrigation?
一个自动喷灌设备，射程20米．这个设备转动一周，喷灌的面积是多少平方米？
<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

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

<result>1_256</result>