The circumference of the bottom of a cylinder is 9.42cm. If the height increases by 2cm and the size of the bottom remains the same, how much does the surface area increase in cm**2?
一个圆柱的底面周长是9.42cm，如果高增加2cm，底面大小不变，那么表面积比原来增加了多少cm**2．
<gadget id="calculator">9.42 * 2</gadget>
<output>18.84</output>

<result>18.84</result>