What is the area of a circle whose circumference is 25.12 decimeters?
一个周长是25.12分米的圆，它的面积是多少平方厘米．
<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

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

<gadget id="calculator">50.24 * 100</gadget>
<output>5_024</output>

<result>5_024</result>