A chocolate biscuit box, the total area of the four sides is 12 square decimeters, the bottom is a square with side length 3 decimeters, what is the volume of this biscuit box?
一个巧克力饼干盒，四个侧面的总面积是12平方分米，底面是边长3分米的正方形，这个饼干盒的体积是多少？
<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<gadget id="calculator">12 / 12</gadget>
<output>1</output>

<gadget id="calculator">3 * 3 * 1</gadget>
<output>9</output>

<result>9</result>