If the sum of the lengths of all the sides of a cuboid intersecting at a vertex is 20 cm, what is the sum of the lengths of all the sides of the cuboid in cm?
如果一个长方体相交于一个顶点的所有棱长之和是20厘米，那么这个长方体的所有棱长总和是多少厘米．
<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<result>80</result>