cheat, you get what you want, your teacher gets what he wants, everyone's happy. Cheated in my science exam, teacher knew i was doing it. But why stop me, I get a gcse and he gets a good reputation for teaching his students well.
Cheat, in my opinion, cheating (in school) is not morally wrong if it comes to the point where it's cheat or fail, it's the same concept as having a choice between stealing food or dying of starvation, sometimes there's just too much on the line to do it the morally correct way.
You tried to make one then turn the best model you made in. Don't take a zero, and don't ask your friend to do it for you. Or have your friend tutor you on it and help you, which is the best idea.