A rectangular iron sheet 60 cm long and 40 cm wide is rolled into a chimney, what is its side area in square centimeters?
将一张长60厘米，宽40厘米的长方形铁皮卷成一个烟筒，它的侧面积是多少平方厘米．
<gadget id="calculator">60 * 40</gadget>
<output>2_400</output>

<result>2_400</result>