The perimeter of the rectangle is 480 meters, its length is known to be 100 meters, what is its width in meters?
长方形的周长是480米，已知它的长是100米，它的宽是多少米？
<gadget id="calculator">480 / 2</gadget>
<output>240</output>

<gadget id="calculator">240 - 100</gadget>
<output>140</output>

<result>140</result>