If the height of a cylinder increases by 2cm and the size of the bottom remains the same, the surface area increases by 37.68cm. What is the area of a base of the cylinder in cm**2.
一个圆柱的高增加2cm，底面大小不变，则表面积增加37.68cm，这个圆柱的一个底面积是多少cm**2．
<gadget id="calculator">37.68 / 2</gadget>
<output>18.84</output>

<gadget id="calculator">18.84 / 3.14 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<result>28.26</result>