A piece of rectangular paper with a length of 45 cm and a width of 15 cm is rolled into a cylindrical paper tube (ignoring the joints), what is the lateral area of the cylinder?
把一张长45cm，宽15cm的长方形纸卷成一个圆柱形纸筒(接头处忽略不计)，这个圆柱的侧面积是多少．
<gadget id="calculator">45 * 15</gadget>
<output>675</output>

<result>675</result>