A 20m long steel pipe is cut into three sections, and the surface area increases by 12.56dm**2 compared to the original one. What is the original volume of this steel pipe?
将一根20m长的钢管截成三段，表面积比原来增加了12.56dm**2，原来这根钢管的体积是多少？
<gadget id="calculator">12.56 / 4</gadget>
<output>3.14</output>

<gadget id="calculator">3.14 * 20 * 10</gadget>
<output>628</output>

<result>628</result>