Build a circular garden whose circumference is 47.1 meters. What is the area of the garden in square meters?
修一个圆形花园，它的周长是47.1米．这个花园的面积是多少平方米？
<gadget id="calculator">2 * 3.14</gadget>
<output>6.28</output>

<gadget id="calculator">47.1 / 6.28</gadget>
<output>7.5</output>

<gadget id="calculator">7.5 ** 2</gadget>
<output>56.25</output>

<gadget id="calculator">3.14 * 56.25</gadget>
<output>176.625</output>

<result>176.625</result>