If the diameter and height of the base of a cylinder are tripled, how many times will its lateral area be enlarged?
把一个圆柱的底面直径和高都扩大到原来的3倍，它的侧面积扩大到原来的多少倍．
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<result>9</result>