A rectangular playground, the length is 2.5 times the width, it can be expanded according to the needs, and the length must be 2 times the width. The designer found that if the length and width of the original rectangular playground were increased by 20 meters each, it would just meet the requirements. How many square meters will the playground area be after the expansion?
一个长方形的操场，长是宽的2.5倍，根据需要将它进行扩建，而且长必须是宽的2倍．设计人员发现，如果把原来长方形操场的长和宽各加20米，那么刚好符合要求，扩建后操场面积是多少平方米？
<gadget id="calculator">2 * 20</gadget>
<output>40</output>

<gadget id="calculator">40 - 20</gadget>
<output>20</output>

<gadget id="calculator">2.5 - 2</gadget>
<output>0.5</output>

<gadget id="calculator">20 / 0.5</gadget>
<output>40</output>

<gadget id="calculator">2.5 * 40</gadget>
<output>100</output>

<gadget id="calculator">100 + 20</gadget>
<output>120</output>

<gadget id="calculator">40 + 20</gadget>
<output>60</output>

<gadget id="calculator">120 * 60</gadget>
<output>7_200</output>

<result>7_200</result>