The sum of the diameters of ten circles of different sizes is 40 cm. What is the sum of the circumferences of these ten circles?
十个大小不一的圆的直径的和是40厘米，这十个圆的周长和是多少．
<gadget id="calculator">3.14 * 40</gadget>
<output>125.6</output>

<result>125.6</result>