Divide a circle into several equal parts, and then assemble it into an approximate rectangle. The width of the rectangle is known to be 3 centimeters. What is the circumference of the original circle in centimeters.
把一个圆等分若干等份，然后把它拼成一个近似的长方形，已知长方形的宽是3厘米，原来圆的周长是多少厘米．
<gadget id="calculator">2 * 3.14 * 3</gadget>
<output>18.84</output>

<result>18.84</result>