The front wheel of a road roller is 4 meters wide and 1 meter in diameter. If the front wheel rolls for two weeks, how many square meters will the road surface be rolled over?
一台压路机的前轮宽4米，直径是1米，前轮滚动两周，压过的路面是多少平方米．
<gadget id="calculator">3.14 * 1 * 2 * 4</gadget>
<output>25.12</output>

<result>25.12</result>