There is a rectangle, if the length is reduced by 6 meters and the width is reduced by 2 meters, the area will be reduced by 52 square meters, and the remaining part is exactly a square. Find the perimeter of this square.
有一个长方形，如果长减少6米，宽减少2米，面积就比原来减少52平方米，且剩下部分正好是一个正方形．求这个正方形的周长．
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<result>20</result>