The diameter of the front wheel of a road roller is 1.8 meters, and it turns 8 times per minute. How many meters does the road roller advance per minute?
一种压路机的前轮直径是1.8米，每分转8圈，压路机每分钟前进多少米？
<gadget id="calculator">3.14 * 1.8 * 8</gadget>
<output>45.216</output>

<result>45.216</result>