The vikings play 36 games this year at midseason they had won 16 games. how many of the remaining games must they win in order to win at least 80% of all their games

80% of their games are 28.8, or 29 games (since they need to win at least 80%). They have already won 16. 29-16 is 13.

Therefore, they need to win 13 more games.

P.S. The midseason statement is irrelevant.

you can use a^2+ b^2=c^2