The lateral expansion of a cylinder is a square. If the height is reduced by 3 decimeters, the surface area is reduced by 94.2 square decimeters. What is the volume of this cylinder in cubic decimeters?
一个圆柱的侧面展开是一个正方形．如果高减少3分米，表面积减少94.2平方分米．原来这个圆柱的体积是多少立方分米？
<gadget id="calculator">94.2 / 3</gadget>
<output>31.4</output>

<gadget id="calculator">31.4 / 3.14</gadget>
<output>10</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25 * 10</gadget>
<output>785</output>

<result>785</result>