The height of a cylinder is 15 cm. If its height is increased by 2 cm, its surface area will increase by 25.12 cm2. Find the volume of the original cylinder.
一个圆柱高为15厘米，把它的高增加2厘米后表面积增加25.12平方厘米，求原来圆柱的体积．
<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 * 15</gadget>
<output>188.4</output>

<result>188.4</result>