Answer:
length = 12 cm
breadth = 9 cm.
perimeter of rectangle = 2( l+b)
= 2(12+9) = 2(21) = 42cm.
New length = (12+x) cm
New breath = (9+x) cm
2(12+x+9+x) = 42×2
2(21+x) = 84
21+ x = 84/2
21+x = 42
x= 42-21= 21
x= 21.
Therefore, length = (12+x)cm
=( 12+21) cm = 33cm.
Step-by-step explanation:
Firstly we have written the length and breadth of the rectangle.
And the perimeter of rectangle i.e. 2(l+b)
Then, as it is in question we have doubled the perimeter
And at last, we have got the value of x.
and by putting the value in the new length we will get our answer.
hope you have got your answer dear.