Cut the largest circle out of a square with a circumference of 8 decimeters, what is the circumference of the circle in decimeters?
在周长是8分米的正方形内剪掉一个最大的圆，圆的周长是多少分米．
<gadget id="calculator">3.14 * 8</gadget>
<output>25.12</output>

<result>25.12</result>