The drum of the road roller is a cylinder. Its cross-sectional area is 1 meter in diameter and 2 meters in length. If it rolls 20 times per minute, how long can it be pressed per minute?
压路机的滚筒式一个圆柱，它的横截面积直径是1米，长是2米，如果每分钟滚20圈，每分钟可以压多长？
<gadget id="calculator">3.14 * 1 * 20</gadget>
<output>62.8</output>

<result>62.8</result>