Use three identical cubes to form a cuboid. The surface area of the cuboid is 84dm**2. What is the surface area of the original cube in dm**2?
用三个完全一样的正方体，拼成一个长方体，长方体的表面积是84dm**2，原来一个正方体的表面积是多少dm**2．
<gadget id="calculator">3 * 6</gadget>
<output>18</output>

<gadget id="calculator">18 - 4</gadget>
<output>14</output>

<gadget id="calculator">84 / 14</gadget>
<output>6</output>

<gadget id="calculator">6 * 6</gadget>
<output>36</output>

<result>36</result>