The sprinkler radius of the automatic rotary sprinkler irrigation device in the park is 5 meters, what is its maximum sprinkler area in square meters?
公园里的自动旋转喷灌装置的喷灌半径是5米，它的最大喷灌面积是多少平方米．
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<result>78.5</result>