The radius of the base of a cylinder is 3 decimeters, if the sides of the cylinder are expanded to obtain a rectangle, then the length of the rectangle may be how many decimeters.
一个圆柱的底面半径是3分米，把这个圆柱的侧面展开得到一个长方形，那么这个长方形的长可能是多少分米．
<gadget id="calculator">3.14 * 3 * 2</gadget>
<output>18.84</output>

<result>18.84</result>