A string is wound around a cylindrical pencil exactly 6 times. The radius of the cross-section of the pencil is 5 mm. What is the length of the string in centimeters?
一根绳子刚好在一支圆柱体铅笔上绕了6圈，铅笔的横截面半径是5毫米，这根绳子长多少厘米．
<gadget id="calculator">3.14 * 2 * 0.5 * 6</gadget>
<output>18.84</output>

<result>18.84</result>