A cylindrical chimney is made of a rectangular iron sheet with a length of 62.8 meters and a width of 31.4 meters. What is the lateral area of the cylinder?
用一块长62.8米，宽31.4米的长方形铁皮做成圆柱形烟囱，圆柱的侧面积是多少．
<gadget id="calculator">62.8 * 31.4</gadget>
<output>1_971.92</output>

<result>1_971.92</result>