The height of a cylinder is 20 cm, if the height is reduced by 3 cm, the surface area is reduced by 94.2 cm2. What is the volume of the original cylinder in cubic centimeters?
一个圆柱的高是20厘米，若把高减少3厘米，则表面积减少94.2平方厘米．原来圆柱的体积是多少立方厘米？
<gadget id="calculator">94.2 / 3</gadget>
<output>31.4</output>

<gadget id="calculator">31.4 / 3.14 / 2</gadget>
<output>5</output>

<gadget id="calculator">3.14 * 5 * 5 * 20</gadget>
<output>1_570</output>

<result>1_570</result>