There is a circular stage in the park with a circumference of 25.12 meters. What is the area of the stage?
公园里有一个圆形表演台，周长是25.12米，这个表演台的面积是多少．
<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>