If the length and width of a rectangle are tripled, how many times will its area be increased?
一个长方形长和宽都扩大3倍，它的面积增加多少倍．
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">9 - 1</gadget>
<output>8</output>

<result>8</result>