The front wheel of the road roller is cylindrical, the width of the wheel is 4m, and the diameter is 15dm. If the front wheel rotates once, what is the area of the road?
压路机的前轮是圆柱形，轮宽4m，直径15dm，前轮转动一周，压路的面积是多少㎡．
<gadget id="calculator">15 / 10</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">3.14 * (3/2) * 4</gadget>
<output>18.84</output>

<result>18.84</result>