A cylinder is formed by a piece of rectangular paper with a length of 25 cm and a width of 16 cm. What is its lateral area in square centimeters?
用一张长25厘米，宽16厘米的长方形纸围成一个圆柱，它的侧面积是多少平方厘米．
<gadget id="calculator">25 * 16</gadget>
<output>400</output>

<result>400</result>