The diameter of a circle is 6 cm. If the diameter of the circle increases to 10 cm, how many cm does the circumference of the circle increase to?
一个圆的直径是6cm，如果这个圆的直径增加到10cm，则这个圆的周长增加到多少cm．
<gadget id="calculator">3.14 * 10</gadget>
<output>31.4</output>

<result>31.4</result>