How many square decimeters of iron sheet should be used to make an uncovered cylindrical iron bucket with a height of 6 decimeters and a bottom radius of 2 decimeters? (Pi takes an integer of 3)
做一个高6分米，底面半径是2分米的无盖圆柱形铁皮水桶，大约要用铁皮多少平方分米？(圆周率取整数3)
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<gadget id="calculator">3 * 2 * 2 * 6</gadget>
<output>72</output>

<gadget id="calculator">12 + 72</gadget>
<output>84</output>

<result>84</result>