Question

the length of a a rectangular field is 20m more than its breadth. if the perimeter of the field is 280m, then what is its length?

Answer 1

Let breadth be x m
so lenghth = x+20
now perimeter=2(l+b)=2(x+x+20)
280/2=2x+20
140/2=x+10
x=70-10=60
so length=60+20=80 m

hope this helps :-)

Answer 2

let the bredth of rectangular field be (x)
so,the length =20+(x)
perimeter=2(l+b)
=2(20+x+x)
280=2(20+2x)
280=40+4x
240=4x
x=240/4
x=60
so
length of rectangular field is x+20=60+20=80