If the base of a cuboid is a square with side length 3 decimeters and a height of 12 decimeters, what is the surface area of the rectangle?
长方体的底面是边长为3分米的正方形，高为12分米，长方形的表面积是多少平方分米．
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">3 * 12</gadget>
<output>36</output>

<gadget id="calculator">9 + 36 + 36</gadget>
<output>81</output>

<gadget id="calculator">81 * 2</gadget>
<output>162</output>

<result>162</result>