The diameter of circle A is 8 cm long, which is 40% of the diameter of circle B. What is the circumference of circle B in centimeters.
甲圆直径长8厘米，是乙圆直径的40%．乙圆的周长是多少厘米．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">8 / (2/5)</gadget>
<output>20</output>

<gadget id="calculator">3.14 * 20</gadget>
<output>62.8</output>

<result>62.8</result>