The length of a rectangle is 18 cm, and the length is twice the width. What is the area of the rectangle?
一个长方形的长是18厘米，长是宽的2倍，这个长方形的面积是多少？
<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">18 * 9</gadget>
<output>162</output>

<result>162</result>