The height of a cylinder is 8 decimeters, if it is cut off by 4 decimeters, its surface area will be reduced by 25.12 square decimeters. What is the volume of the original cylinder in cubic decimeters?
一个圆柱体的高是8分米，如果把它截去4分米，它的表面积就减少了25.12平方分米．原来圆柱体的体积是多少立方分米？
<gadget id="calculator">25.12 / 4 / 3.14 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 8</gadget>
<output>25.12</output>

<result>25.12</result>