A piece of rectangular white paper with a length of 20 cm and a width of 15 cm is rolled into a cylinder. What is the lateral area of the rolled cylinder in square centimeters?
用一张长20厘米、宽15厘米的长方形白纸卷成一个圆柱体，卷成的圆柱体的侧面积是多少平方厘米．
<gadget id="calculator">20 * 15</gadget>
<output>300</output>

<result>300</result>