rectangle has a perimeter of 84 meters and the ratio of length to width is 5:2. What is the area of the rectangle?
一个长方形周长84米，长和宽的比是5：2，这个长方形的面积是多少平方米？
<gadget id="calculator">84 / 2</gadget>
<output>42</output>

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

<gadget id="calculator">42 * (5/7)</gadget>
<output>30</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">42 * (2/7)</gadget>
<output>12</output>

<gadget id="calculator">30 * 12</gadget>
<output>360</output>

<result>360</result>