You can put this solution on YOUR website!
Let x = the length of the second side
The first side is 5 metres longer, so the first side is x+5
The third side is four times the length of the second, so it is 4x.
Perimeter of a triangle, just add the 3 sides up:
P = (x+5) + x + 4x
65 = 6x + 5
60 = 6x
x = 10
The second side is 10 meters.