Redirection can be useful to manage anger. Arguing with someone with dementia isn’t helpful—it often adds to their frustration and anger.
Gently acknowledging that you can see they are angry and taking the blame—although you didn’t do anything wrong—may also help ease the situation. For example, you can say, “Dad, I’m sorry you are so upset, and I’m sorry for anything I did that upset you. Even though you are mad at me right now, I’m wondering if you’d like to watch your favorite TV program with me.”