A circular garden has a radius of 3 meters. Build a circular path around it, what is the length of the path in meters?
一个圆形花园，量得这个花园的半径是3米．沿周围修一条环形小路，小路的长是多少米？
<gadget id="calculator">2 * 3.14 * 3</gadget>
<output>18.84</output>

<result>18.84</result>