Question 167365
let 'l' be the length and  'w' be the width of the flag.

then perimeter  = 2l +2w ( rectangle)

   given, perimeter = 28 ft
  i.e. 2l +2w = 28 ft
        2 (l +w) = 28 
           l + w = 28 /2 = 14 ..........(1)

given length is 4 ft less than its width
         i.e . l =  w - 4  ...........(2)

from (1) & (2)

         w - 4 + w = 14 
           2w - 4 = 14 

            2w =  14+4

             2w  = 18 
               w = 18 /2 = 9ft 

   l  =  w - 4 = 9 - 4  = 5 ft