There is a rectangular square, and 2 meters are drawn along its two different sides as a green belt, and the rest is still a rectangle with a circumference of 280 meters. What is the area of the green belt in square meters?
有一块长方形广场，沿着它不同的两条边各划出2米做绿化带，剩下的部分仍是长方形，周长为280米．绿化带的面积是多少平方米？
<gadget id="calculator">280 / 2</gadget>
<output>140</output>

<gadget id="calculator">140 * 2</gadget>
<output>280</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">280 + 4</gadget>
<output>284</output>

<result>284</result>