List four ways that a memoir and biography are similar do not give me simple answers like they both are non-fiction or they both use point of view. give me something out of the box at least. if you can only think of three that's fine.

A memoir is something you'd create in order to remember someone/something and a biography is something you'd write about someone else. Both won't include detailed emotions that the subject is feeling and both are wrote by someone who isn't the subject. Finally, they are both directed to a wider ordiance but are focussed on one particular subject (person).
Hope this helps!