Question

if the length and the breadth of a room are increased by 1 m each the area is increased by 21 square metre if the length is decreased by 1 m and the breadth is increased by 2 metre the area is increased by 14 square metre find the perimeter of a room

Answer 1

Answer:

Step-by-step explanation:

Let original length be= l

Let the original breadth be= b

Area= l*b

Length= l+1

Breadth= b+1

Area= l*b+21

Therefore:

(l+1)(b+1)=l*b+21

l*b+l+b+1= l*b+21

l*b-l*b+l+b= 21-1

l+b= 20

Perimeter= 2(l+b)

=>2(20)

=>40m

THIS IS THE SHORTCUT METHOD....... THROUGH THE OTHER METHOD YOU CAN FIND THE LENGTH AND BREADTH. IF YOU WANT I CAN SHOW THAT AS WELL.