The sum of the sides of a cuboid is 42 centimeters, what is the sum of the three sides starting from a vertex in centimeters?
一个长方体的棱长和是42厘米，从一个顶点出发的三条棱的和是多少厘米．
<gadget id="calculator">42 / 4</gadget>
<output>21/2 = around 10.5</output>

<result>21/2 = around 10.5</result>