A sheep is tied to a stake in the grass, and the rope is 3 meters long. What is the maximum area in square meters that the sheep can eat grass?
在草地的木桩上栓着一只羊，绳长3米，这只羊能吃到草的面积最大是多少平方米？
<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

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

<result>28.26</result>