After cutting a 3-meter-long cylinder into 3 sections, the surface area increases by 12.56 square decimeters. What is the original volume of the cylinder?
把一个长3米的圆柱截成3段后，表面积增加了12.56平方分米，这个圆柱原来的体积是多少平方分米．
<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>