The side view of a cylinder is a square. The radius of the base of the cylinder is 3 cm. What is the height of the cylinder in cm?
一个圆柱的侧面展开图是一个正方形，这个圆柱的底面半径是3厘米，圆柱的高是多少厘米．
<gadget id="calculator">3.14 * 2 * 3</gadget>
<output>18.84</output>

<result>18.84</result>