A cuboid whose base is a cube has the sum of its sides 84 cm and its height 5 cm, what is its volume in cubic centimeters?
一个底面是正方体的长方体，它的棱长和是84厘米，高是5厘米，它的体积是多少立方厘米．
<gadget id="calculator">84 / 4</gadget>
<output>21</output>

<gadget id="calculator">21 - 5</gadget>
<output>16</output>

<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<gadget id="calculator">4 * 4 * 5</gadget>
<output>80</output>

<result>80</result>