Cut a circle with the largest area on a piece of rectangular paper with a length of 16 cm and a width of 8 cm. What is the circumference of this circle in cm?
在一张长16厘米，宽8厘米的长方形纸上剪一个面积最大的圆，这个圆的周长是多少cm．
<gadget id="calculator">3.14 * 8</gadget>
<output>25.12</output>

<result>25.12</result>