Uncle Li is going to build a chicken coop with a 31.4-meter fence against a wall. What is the maximum area of the chicken coop in square meters?
李叔叔准备用31.4米的篱笆靠一堵墙修建一个鸡舍，这个鸡舍的面积最大是多少平方米．
<gadget id="calculator">31.4 / 3.14</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">100 / 2</gadget>
<output>50</output>

<gadget id="calculator">3.14 * 50</gadget>
<output>157</output>

<result>157</result>