A cylinder with a height of 5 cm, if its height increases by 3 cm, then its surface area increases by 18.84 cm**2. What is the volume of the original cylinder?
一个高为5cm的圆柱，如果它的高增加3cm，那么它的表面积就增加18.84cm**2．原圆柱的体积是多少？
<gadget id="calculator">18.84 / 3 / 3.14 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 5</gadget>
<output>15.7</output>

<result>15.7</result>