Uncle Wang built a chicken coop on one wall of his house. He wanted to use a 12-meter-long bamboo fence to enclose the largest chicken coop. Think carefully about how to build the chicken coop with the largest area and how many square meters the area is.
王大伯在自家的一面墙建一个鸡舍，想用12米长的竹篱笆围出最大的鸡舍，仔细想想，怎样建鸡舍的面积最大，面积是多少平方米．
<gadget id="calculator">3 * 6</gadget>
<output>18</output>

<result>18</result>