The school has a circular flower bed with a perimeter of 12.56 meters. How many square meters does this flower bed occupy?
学校有一个圆形花坛，花坛的周长是12.56米．这个花坛的占地面积是多少平方米？
<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<result>12.56</result>