Use a rectangular piece of paper with a length of 18.84 cm and a width of 9.42 cm as the side area to form a cylinder as long as possible (regardless of the joints). Which of the following circles can match this cylinder as the bottom surface. r= how many centimeters
用一个长18.84厘米，宽9.42厘米的长方形纸片当做侧面积围成一个尽可能长的圆柱(不考虑接头处)，下面哪个圆可以配上这个圆柱当底面．r=多少厘米
<gadget id="calculator">9.42 / 3.14 / 2</gadget>
<output>1.5</output>

<result>1.5</result>