Question

The length of a rectangular field is 8meters less than twice its breadth. If the perimeter of a rectangular field is 56 meters, find its length and breadth ?

Answer 1

let the breadth of rectangle(b) = x m
then length(l) = (2x-8) m
A/q,
      perimeter of rectangle = 56 m
⇒  2(l+b) = 56
⇒  2(2x-8+x) = 56
⇒    3x-8 = 28
⇒     3x =28+8
⇒     x = 36/3 = 12 m
therefore length(l) = 2x-8 =2×12 - 8 =16 meters
               breadth(b) = x = 12 meters

Answer 2

let the breadth be x
therefore. length=2x-8
  the total perimeter=2(l+b)=56
                               ⇒l+b=28
                               ⇒x+2x-8=28
                              ⇒3x=36
                              ⇒x=12
so the breadth is 12 m and length is 16m