Let the two parts with equal length have length x.
The longer part has length x + 20.
The sum of the three lengths is 695 m.
x + x + x + 20 = 695
3x + 20 = 695
3x = 675
x = 225
x + 20 = 245
The two short parts measure 225 m, and the long part measures 245 m.