cylinder whose base circumference is equal to its height, if its height is shortened by 1 cm, its surface area will be reduced by 6.28 cm2, what is the volume of this cylinder in cubic centimeters?
一个底面周长和高相等的圆柱，如果高缩短1厘米，它的表面积就减少6.28平方厘米，求这个圆柱的体积是多少立方厘米？
<gadget id="calculator">6.28 / 1 / 3.14 / 2</gadget>
<output>1</output>

<gadget id="calculator">6.28 / 1</gadget>
<output>6.28</output>

<gadget id="calculator">3.14 * 1 * 1 * 6.28</gadget>
<output>19.7192</output>

<result>19.7192</result>