There is a circular flower bed with a diameter of 3 meters. If you walk around it, how many meters will you walk?
有一个圆形花圃的直径是3米，如果绕着它的周围走一圈，要走多少米．
<gadget id="calculator">3.14 * 3</gadget>
<output>9.42</output>

<result>9.42</result>