Cut out two largest circles on a piece of rectangular paper with a length of 8 decimeters and a width of 4 decimeters. What is the circumference of each circle in decimeters?
在一张长8分米，宽4分米的长方形纸上剪下两个最大的圆，每个圆的周长是多少分米．
<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<result>12.56</result>