Final answer:
Gawain has broken his wager with Berilak by accepting the gift of the green girdle from Bertilak's wife.
Step-by-step explanation:
Gawain has now broken his wager with Berilak by accepting the gift of the green girdle from Bertilak's wife. According to their agreement, Gawain was supposed to exchange all the winnings of each day with Bertilak, while Bertilak would give Gawain anything he won during the hunt. However, Gawain broke the agreement by not exchanging the girdle, which he received on the third day of the hunt.