On the stake in the grass, tie a lamb with a length of 3 meters. How many square meters of grass can this sheep eat at most?
在草地的木桩上用3米长的拴住一只小羊．这只羊最多可以吃到多少平方米的草？
<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<result>28.26</result>