The length and width of a cuboid are both 3dm and the height is 7dm. What is the sum of the lengths of the sides in dm?
长方体长、宽均为3dm，高7dm，棱长总和是多少dm．
<gadget id="calculator">3 + 3 + 7</gadget>
<output>13</output>

<gadget id="calculator">13 * 4</gadget>
<output>52</output>

<result>52</result>