Let 'L' be the length of the area
     'W' be the width of the area
With the given data that the area is 308 sq.m and that when the length is 2 meters less and the the width is 6 meters more you'll have a square, we may find the dimensions using the formula for area of a quadrilateral which is A = LW and the equation L-2=W+6 as the equivalent mathematical expression for the second data. Rearranging the 2nd equation, L-2=W+6 to find the value of length in terms of W you'll have L=W+8 then substituting it to the first equation, A=LW where area is known to be as 308 then, 308=(W+8)(W).. Simplifying further you'll get W=14 and by substitution, L=22