The perimeter of a rectangle is 36cm, and the length is twice the width. What is the area of the rectangle in cm**2.
一个长方形周长是36cm，长是宽的2倍，这个长方形面积是多少cm**2．
<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">36 / 2 / 3</gadget>
<output>6</output>

<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<gadget id="calculator">12 * 6</gadget>
<output>72</output>

<result>72</result>