This seems so simple and maybe I'm missing something, but why can't I set Assignment type to "Page" or "File" when adding an assignment? I know that I can edit a new assignment's description to essentially create html content, but why can't I just select a page that already exists? Its tedious to have to go into Pages and have to cut and copy the content there into an assignment. Plus if I am linking to that information (page) elsewhere, I have to make sure to update it in two places!
The only options that present themselves when adding an assignment are (see screenshot):
I would like the assignment to open a page that I've already written or for that matter a PDF file that includes explanatory information, links and more.