Bend the rope and pass through the place where the rope is to be tied. The long rope is the main rope and the short rope is the auxiliary rope.
Bend the main rope and put it over.
The auxiliary rope wraps around the main rope once.
Then put the auxiliary rope in the past, as shown in the figure.
Pull the main rope to form the trailer cover.
When not in use, the trailer cover can be easily removed by pulling the auxiliary rope.