To make a cuboid water tank with a cover, the bottom surface is a square with a side length of 3 decimeters, and the height is 0.8 meters. How much iron sheet should be used at least?
做一个带盖的长方体水箱，底面是边长3分米的正方形，高是0.8米，至少用多少铁皮？
<gadget id="calculator">0.8 * 10</gadget>
<output>8</output>

<gadget id="calculator">3 * 4 * 8</gadget>
<output>96</output>

<gadget id="calculator">3 * 3 * 2</gadget>
<output>18</output>

<gadget id="calculator">96 + 18</gadget>
<output>114</output>

<result>114</result>