A cylinder with a height of 6 cm, if its height increases by 2 cm, then its surface area increases by 25.12 cm**2, what is the original volume of the cylinder in cubic centimeters?
一个高为6cm的圆柱，如果它的高增加2cm，那么它的表面积就增加25.12cm**2，这个圆柱原来的体积是多少立方厘米？
<gadget id="calculator">25.12 / 2 / 3.14 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 6</gadget>
<output>75.36</output>

<result>75.36</result>