If the circumference of a circle is 3.14 meters, what is its area in square meters?
一个圆的周长是3.14米，它的面积是多少平方米．
<gadget id="calculator">2 * 3.14</gadget>
<output>6.28</output>

<gadget id="calculator">3.14 / 6.28</gadget>
<output>0.5</output>

<gadget id="calculator">0.5 ** 2</gadget>
<output>0.25</output>

<gadget id="calculator">3.14 * 0.25</gadget>
<output>0.785</output>

<result>0.785</result>