A cylinder is surrounded by a square iron sheet with a side length of 12 cm. What is the lateral area of this cylinder in cm**2.
用一张边长为12cm的正方形铁皮，围成一个圆柱，这个圆柱的侧面积是多少cm**2．
<gadget id="calculator">12 * 12</gadget>
<output>144</output>

<result>144</result>