cuboid frame is surrounded by an 84cm iron wire. The ratio of length, width and height is 4:2:1. What is the volume of this cuboid in square centimeters?
用一根84cm的铁丝围成一个长方体框架，长、宽、高的比是4：2：1，这个长方体的体积是多少平方厘米？
<gadget id="calculator">84 / 4</gadget>
<output>21</output>

<gadget id="calculator">4 + 2 + 1</gadget>
<output>7</output>

<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">21 * (4/7)</gadget>
<output>12</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">21 * (2/7)</gadget>
<output>6</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">21 * (1/7)</gadget>
<output>3</output>

<gadget id="calculator">12 * 6 * 3</gadget>
<output>216</output>

<result>216</result>