If a cylinder with a base diameter of 3 cm is unfolded to form a square, what is the height of the cylinder in cm?
一个底面直径是3cm的圆柱体侧面展开后，正好得到一个正方形，那么这个圆柱体的高是多少cm．
<gadget id="calculator">3.14 * 3</gadget>
<output>9.42</output>

<result>9.42</result>