A cylindrical log with a length of 2 meters is now cut into 3 equal sections along its cross section, and the surface area has increased by 80 square decimeters compared to the original one. What is the original volume of this log in cubic decimeters?
一根长2米的圆柱形木料，现在沿着它的横截面截成相等的3段，表面积比原来增加了80平方分米，原来这根木料的体积是多少立方分米．
<gadget id="calculator">80 / 4</gadget>
<output>20</output>

<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">20 * 20</gadget>
<output>400</output>

<result>400</result>