The roller of a road roller is 1.6 meters long and 0.5 meters in diameter. How many square meters is the road covered by this road roller in one round?
一台压路机的滚筒长1.6米，直径是0.5米．这台压路机滚动一周压过的路面是多少平方米？
<gadget id="calculator">3.14 * 0.5 * 1.6</gadget>
<output>2.512</output>

<result>2.512</result>