The perimeter of a rectangle is 36 meters. It is known that the length is three times the width. What is the area of the rectangle?
一个长方形的周长是36米，已知长是宽的3倍，这个长方形的面积是多少．
<gadget id="calculator">1 + 3</gadget>
<output>4</output>

<gadget id="calculator">36 / 2 / 4</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">(9/2) * 3</gadget>
<output>27/2 = around 13.5</output>

<gadget id="calculator">(27/2) * (9/2)</gadget>
<output>243/4 = around 60.75</output>

<result>243/4 = around 60.75</result>