I'm pretty sure it should be. It should look something like:
"two-month engagement"
I'm not too sure about this. However, I would say that it is Ok to say attached is the assignment. It seems wrong, but to make it seem more natural, maybe try adding extra words like requested.
<span>He decides that Hermia will marry Lysander, and that Helena will marry Demetrius along with him and Hippolyta.
</span>
