The perimeter of a rectangle is twice that of the square. The side length of the square and the width of the rectangle are both 6 cm. What is the length of the rectangle in cm?
一个长方形的周长是正方形的2倍，正方形的边长与长方形的宽都是6厘米，长方形的长是多少厘米？
<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<gadget id="calculator">24 * 2</gadget>
<output>48</output>

<gadget id="calculator">48 / 2</gadget>
<output>24</output>

<gadget id="calculator">24 - 6</gadget>
<output>18</output>

<result>18</result>