Use iron sheets to make cylindrical oil drums, water barrels without lids, and chimneys. The radius of the bottom surface is 4 decimeters, and the height is 6 decimeters. How many square decimeters of iron sheets are used for each? (interface not counted)
用铁皮做圆柱形油桶，无盖水桶，烟筒各一个，底面半径都是4分米，高都是6分米，各用铁皮多少平方分米？(接口处不计)
<gadget id="calculator">3.14 * 2 * 4 * 6</gadget>
<output>150.72</output>

<result>150.72</result>