Given a travel related situation, and given a specific question about the situation, summarize the question into a title

The dimensions permitted for Ryanair's small hand luggage are 35x20x20. An Eastpak backpack is about 45x38x11. Will it be allowed on board?
Please refer your personal experiences on this subject.

EDIT: What if I carry it nearly empty and folded into 2 parts, so that it'll fit? (I really need to take a backpack with me, but there's no room in my other luggage, that's why I'm asking these questions)
Eastpak backpack as small luggage with Ryanair?