28 meters long iron wire is used to form a rectangle. The ratio of length to width of this rectangle is 5:2. What is the area of this rectangle?
用28米长的铁丝围成一个长方形，这个长方形的长和宽的比是5：2，这个长方形的面积是多少？
<gadget id="calculator">28 / 2</gadget>
<output>14</output>

<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">14 * (5/7)</gadget>
<output>10</output>

<gadget id="calculator">14 - 10</gadget>
<output>4</output>

<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<result>40</result>