Need some rook and pawns vs rook and pawns analysis
Sort:
are you white?
Black
4...Rc1+ and 5...f5 are absolutely necessary. But it might not be enough.
The rule of thumb in that kind of endgames is that it's a race. If you cannot stop your opponent, you have to run faster to promotion, and here, you have absolutely no chance to stop the two connected passers with the king so far away.