The roller of a road roller is 3 meters long and has a radius of 1.5 meters. If it rolls 7 times, how many square meters is the rolling area?
一台压路机的滚筒长3米，半径为1.5米，如果滚动7周，那么压路面积是多少平方米？
<gadget id="calculator">2 * 3.14 * 1.5 * 3 * 7</gadget>
<output>197.82</output>

<result>197.82</result>