This was an online game I just finished (1 move per 24 hrs). In the mid game my opponent gave me a pawn to open a line against my king, and I took it. I was able to generate some threats on his king though so he couldn't make use of his open file. It reduced to a rook and pawn endgame with me still a pawn up. I used a dubious pawn sacrifice to try to break through, and both lost the pawn and gave my opponent the advantage. However, I used the threat of a passed pawn to clean up his two passed pawns and draw.
How could I have won this rook and pawn endgame? Or are there any other opportunities I missed?
Thanks for the analysis, but those are mostly variations for Black. I played White in this game. How could White have broken through?