Cutting a 3-meter-long round steel into three sections increases the surface area by 12.56 square decimeters. Find the volume of the round bar.
把一根3米长的圆钢截成三段，表面积增加了12.56平方分米．求圆钢的体积．
<gadget id="calculator">12.56 / 4</gadget>
<output>3.14</output>

<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<gadget id="calculator">3.14 * 30</gadget>
<output>94.2</output>

<result>94.2</result>