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 the length = L
⇒ Breadth = L - 20
Perimeter = 2L + 2(L - 20) = 280

2L + 2L - 40 = 280
4L  = 280 - 40
4L = 240
L = 240/4
L = 60

∴ The length = 60 m

Answer 2

Answer:

The length of the floor is 80 m.

Step-by-step explanation:

Let the breadth of the floor be x

Since we are given that the length of the floor is 20 more than  its breadth

So, length = 20 + x

Perimeter of rectangle=$2(l+b)$

where l is the length .

b is the breadth.

So, Perimeter of rectangle=$2(20+x+x)$

                                           =$2(20+2x)$

Since we are given that the perimeter of the floor is 280 m

So, $280=2(20+2x)$

$140=20+2x$

$140-20=2x$

$120=2x$

$60=x$

Thus the breadth is 60 m

Length = 20 +x = 20+60 =80 m

Hence the length of the floor is 80 m.