Two identical squares are put together to form a rectangle, and the perimeter is reduced by 8 meters. What is the length of the rectangle in meters?
两个一样的正方形拼成一个长方形，周长减少了8米，这个长方形的长是多少米．
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<result>8</result>