The diameter of a circular flower bed is 3 meters, and a railing is surrounded 0.8 meters away from the flower bed. How many meters is the total length of the railing?
一个圆形花坛的直径是3米，在离花坛0.8米外，围上一圈栏杆，栏杆全长多少米？
<gadget id="calculator">3 + 0.8 + 0.8</gadget>
<output>4.6</output>

<gadget id="calculator">3.14 * 4.6</gadget>
<output>14.444</output>

<result>14.444</result>