There is a stake on the grass, and a sheep is tied to the stake with a rope. If the rope is 3 meters long, how many square meters of grass can the sheep eat at most? (knots are ignored)
草地上有一根木桩，把一只羊用绳子系在木桩上．如果绳子长3米，这只羊最多可以吃到多少平方米的草？(打结处忽略不计)
<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

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

<result>28.26</result>