The side view of a cylinder is a square. The radius of the base of the cylinder is 30 cm. What is the height of the cylinder in cm?
圆柱体的侧面展开图是正方形，这个圆柱的底面半径是30厘米，这个圆柱体的高是多少厘米．
<gadget id="calculator">2 * 3.14 * 30</gadget>
<output>188.4</output>

<result>188.4</result>