There is a stake in the pasture, and a sheep is tied to the stake with a rope. If the length of the rope is 3 meters, how many square meters of grass can the sheep eat at most?
草场上有一根木桩，把一只羊用绳系在木桩上，如果绳子长是3米，这只羊最多能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>