Verified Answer :

If the perimeter is 84 then 2 sides = 42

10x +11x = 42
21x= 42
x=2

11x 2= 22
10 x 2= 20

hope this helps

TSO

A ratio of 11x to 10x

Where x is a number to keep the ratio the same.

Perimeter = 84

Perimeter = 2 (Length + breadth)

84 = 2 ( 11x + 10x)
84 = 2(21x)
21x = 42
x=2

So that means the actual length of the sides would be:

11 x 2 : 10 x 2
22 : 20

So that means the length can be 22, and the breadth will be 20.
Or the length is 20, and the breadth is 22.