Question

Q.15. The perimeter of a rectangle is 9 times its breadth and its length is 3 cm more than twice its breadth. Find the dimensions of the rectangle.
(Ans: l = 7, b = 2)

Answer 1

Hi,
let the length of the rectangle be = x
let the breath of the rectangle be = y

Therefore the perimeter = 2(x+y)units.

as its length is 3 cm more then twice its breath
therefore
x = 2y +3 ......(1)

As perimeter is 9 times its breath
Therefore, 2(x+y) = 9y
​ ,2x +2y = 9y
, 2x =9y- 2y
,2x = 7y
,x = 7y/2 .....(2)
By puting the value of x from result( 2) in result (1_)we get..

​ x = 2y +3
​ ​ 7y/2 = ​ 2y +3
​7y = 2​ (2y +3)
​7y​ = 4y+ 6
7y - 4y =6
3y= 6
y=2 ......(3)
By putting the value of y from result (3) in result (1) we get,..

​ x = 2y +3
x = 2(2) +3
x=4+3
x=7
Hence,length =7 cm and breath = 2 cm
​Regards