A 80 cm iron wire is welded exactly to form a cuboid with a length of 9 cm, a width of 7 cm, and a height of how many cm.
用一根80厘米的铁丝恰好焊成一个长9厘米，宽7厘米，高多少厘米的长方体．
<gadget id="calculator">80 / 4</gadget>
<output>20</output>

<gadget id="calculator">9 + 7</gadget>
<output>16</output>

<gadget id="calculator">20 - 16</gadget>
<output>4</output>

<result>4</result>