There are two rectangular lands; one belongs to A and the other belongs to B. The length of A is 3 m more than that of B, and the breadth of A is 6 m less than that of B. The area of rectangular land belonging to A is 9 m² more than that of B. If the ratio of the perimeter of rectangular land belonging to A to that of B is 21: 22, then find the length of rectangular land belonging to B.
1
18 m
2
15 m
3
19 m
4
17 m
5
14 m