Question 415063
breadth = x 
length = 2x
..
perimeter = 2*(L+B)
=2(2x+x)
=6x
6x= 3/5
6x*5=3
30x=3
x=1/10 km = 100 m
Length = 100*2=200 m
...
(100+100+200+200)* 5 = 3000 m= 3km