rectangular playground has a perimeter of 180m and a ratio of length to width of 5:4. What is the area of the playground in square meters?
一个长方形操场，周长是180m，长与宽的比是5：4，这个操场的面积是多少平方米？
<gadget id="calculator">180 / 2</gadget>
<output>90</output>

<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">90 * (5/9)</gadget>
<output>50</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">90 * (4/9)</gadget>
<output>40</output>

<gadget id="calculator">50 * 40</gadget>
<output>2_000</output>

<result>2_000</result>