How much dm does the surface area increase when a cube with an edge length of 3dm is cut into two cuboids along the cross section**2.
把一个棱长为3dm的正方体沿横截面切成两个长方体后表面积增加了多少dm**2．
<gadget id="calculator">3 * 3 * 2</gadget>
<output>18</output>

<result>18</result>