A 1.8-meter-long section of round steel is cut into three sections parallel to the bottom surface at a ratio of 2:4:3, and the surface area increases by 20 square centimeters. Of the three sections of round steel, what is the volume of the longest section in cubic centimeters?
把1.8米长的一段圆钢按2：4：3平行于底面截成三段，表面积增加了20平方厘米．这三段圆钢中，最长的一段体积是多少立方厘米．
<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">2 + 4 + 3</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">5 * 1.8 * 100 * (4/9)</gadget>
<output>400</output>

<result>400</result>