A road roller has a cylindrical front wheel with a width of 2 meters and a diameter of 1.2 meters. How many meters does the roller advance when the front wheel rotates once?
一台压路机的前轮是圆柱形，轮宽2米，直径是1.2米．前轮转动一周，压路机前进多少米？
<gadget id="calculator">3.14 * 1.2</gadget>
<output>3.768</output>

<result>3.768</result>