An automatic sprinkler device, the longest distance of spraying water is 20 meters, how large area can this sprinkler spray water on flowers and plants?
一种自动喷水装置，喷水的最远距离是20米，这种喷水装置可以给多大面积范围内的花草喷水？
<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

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

<result>1_256</result>