A cylindrical road roller has a radius of 80 cm and a width of 2 meters. What is the area in square meters that the road roller rolls over in one revolution?
一个圆柱型压路机，半径是80厘米，宽2米，那么压路机转动一圈压过的面积是多少平方米．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">3.14 * (4/5) * 2 * 2</gadget>
<output>10.048</output>

<result>10.048</result>