"SEGMENT" should be listed in the index at the back of the book. As should "TABLESPACE". You should be able to find the section on resizing a tablespace in the sections just after Tablespaces are introduced. Which course is this for, anyway?
Why not? Your first question doesn't allow for help since the question makes no sense. My pointing that out, should lead you to realise that you need to try to formulate the question in such a way that it does make sense. I'd say that, if you understand that, the it has been helpful.
The second response is very helpful if you are willing to spend just a little bit of time reading. I even showed you how you can use a search engine called google to ask similar questions and get answers with all your very own work. But maybe you're not willing to actually do the work (I'm surprised you could muster the energy to post on this forum -twice. Must've been a real hardship)