The circumference of a circular flower bed is 31.4 meters, how many square meters does it cover?
一个圆形花坛的周长为31.4米，它的占地面积是多少平方米？
<gadget id="calculator">31.4 / 3.14 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<result>78.5</result>