A circular tabletop has a perimeter of 25.12 decimeters. What is the area of this circular tabletop in square decimeters?
一张圆形桌面，它的周长是25.12分米，这张圆形桌面的面积是多少平方分米？
<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>