The perimeter of a cylindrical base is equal to its height. If the height increases by 2 cm, the surface area increases by 25.12 cm2. Please calculate the original volume of this cylinder?
一个圆柱形的底面周长和高相等，如果高增加2厘米，表面积就增加25.12平方厘米．请你计算出这个圆柱原来的体积是多少？
<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 * 3.14 * 4</gadget>
<output>157.7536</output>

<result>157.7536</result>