A cuboid is 8 cm long. If the height is increased by 3 cm and the length and width remain the same, it will become a cube. What is the sum of the lengths of the sides of the original cuboid?
一个长方体，长8厘米．如果高增加3厘米，长和宽都不变，就会成为正方体．原来长方体棱长总和是多少厘米？
<gadget id="calculator">8 - 3</gadget>
<output>5</output>

<gadget id="calculator">8 + 8 + 5</gadget>
<output>21</output>

<gadget id="calculator">21 * 4</gadget>
<output>84</output>

<result>84</result>