Question

The length of a rectangular floor is 20m more than its breadth if the perimeter of the floor is 280m what is the length

Answer 1

Let breadth of the rectangle be x m
length = 20+x
Perimeter=280m
2(l+b)=280
2(20+x+x)=280
20+x+x=280/2
20+2x=140
2x=140-20
2x=120
x=60

breadth of the rectangle=x=60m
length of the rectangle=20+x
=20+60=80m
breadth is 60m and length is 80m.

Answer 2

the perimeter of a rectangle= 2l+2b
let l be length
here ,
2l+2b=280
l=20+b
thus,
2(20+b)+b=280
40+2b+b=280
3b=240
b=240/3
so b=60
b value in 2l+2b=280
we get 2l+120=280
2l=160
thus l=80.