A yurt with a circular base has a circumference of 25.12 meters measured along the ground. How many square meters does it cover?
一个底面是圆形的蒙古包，沿地面量得周长是25.12米．它的占地面积是多少平方米．
<gadget id="calculator">25.12 / 3.14 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<result>50.24</result>