Question 494301
Given
Perimeter of rectangle = 36
Length = Twice the Width 
l=2*w ........(1)
We know 
Perimeter of rectangle = 2*length + 2*width
P=2l+2w
36=2l+2w
Put the value of l in above equation we have
36=2(2w)+ 2w
36=4w+2w
36=6w
or we can write
6w=36
w=36/6
w=6
Put the value of w in (1)
l=2w ........(1)
l=2*6
l=12

Length is 12 and Width is 6 meters