Pls how can i add text to this model

I enjoyed designing the hammer and was fascinated by the use of the (isolate) command, but I don't understand why we use so many fillet features that we can use one or two for each body. Is it to leave room for editing, or is it easier for the tutorial?

Can someone help me understand what I am doing wrong here I'm trying to make a motion study to see how solid body contact works, and it does, but only on the bottom part and not the sides. there is a .mp4 video below

I liked the use of the surface tab features and I think that I over looked how useful it is Are there any thing i have to keep in mind when using surfaces?

What are the diffrant ways I can make this 20deg and what is the best way to do it