The perimeter of a rectangle is 54 meters, and the ratio of its length to width is 5:4. What is the area of the rectangle?
一个长方形的周长为54米，它的长与宽的比是5：4，这个长方形的面积是多少？
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">54 / 2 / 9</gadget>
<output>3</output>

<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<gadget id="calculator">15 * 12</gadget>
<output>180</output>

<result>180</result>