A sheep is tied to the grass, and the rope is 6 meters long. What is the maximum area that the sheep can eat grass?
草地上栓着一只羊，绳子长6米，羊吃到草的最大面积是多少？
<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

<gadget id="calculator">3.14 * 36</gadget>
<output>113.04</output>

<result>113.04</result>