A 90 cm long iron wire surrounds a rectangle whose length to width ratio is 2:1. What is the area of the rectangle?
用一根90厘米长的铁丝围一个长与宽的比是2：1的长方形，这个长方形的面积是多少？
<gadget id="calculator">90 / 2</gadget>
<output>45</output>

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">45 * (2/3)</gadget>
<output>30</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">45 * (1/3)</gadget>
<output>15</output>

<gadget id="calculator">30 * 15</gadget>
<output>450</output>

<result>450</result>