By solving a simple linear equation, we conclude that the length of the second lawn is 10 meters.
We know that one of the lawns is 5 meters long and 4 meters wide, then its area is:
A = 4m*5m = 20m^2
The other is two times as big, so its area is 40m^2 and has the same width as the first one (4 meters), so if we define the length as L we can write:
40m^2 = 4m*L
Solving for L we get:
(40 m^2)/4m = L = 10m
The length is 10 meters.
If you want to learn more about area, you can read:
https://brainly.com/question/24487155
