A cuboid iron sheet bucket, the bottom surface is a square with a side length of 3 decimeters, and the height of the bucket is 7.2 decimeters. How many square decimeters of iron sheets are needed to make such a pair of buckets without lids?
一个长方体铁皮水桶，底面是边长为3分米的正方形，水桶高7.2分米，做这样一对无盖的水桶，至少需要多少平方分米的铁皮？
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">3 * 4 * 7.2</gadget>
<output>86.4</output>

<gadget id="calculator">9 + 86.4</gadget>
<output>95.4</output>

<gadget id="calculator">95.4 * 2</gadget>
<output>190.8</output>

<result>190.8</result>