Hello! I’m new to learning blender and I’ve stumbled upon a problem I can’t figure out. For context, I’m trying to recreate this shelf and I also included what I’ve made so far:
https://imgur.com/a/OH10nyq
I wanted to delete the top since the top shelf is open. But it kinda gave me this awkward slanted unfilled area and I was wondering how do I fill in this area? And not make it slant?
Would really appreciate any help!
There are differents ways to do that depending the result you want.
First, in the Edit Mode, select the face, press I to use Inset Face tool 
, then press E to Extrude
Another way is, in Edit Mode, select two faces (eg. Top and Bottom), press I to use Inset Face tool, click on Edge Menu > Bridge Edge Loops
Sorry, I tried to upload images but I can’t upload yet. I’m new user here!
I would suggest that you go a different route rather than adding and subtracting geometry …and jumping through all the suggested hoops… and just use a Boolean Modifier …
Set the size of the first Cube for the shelf, then add another cube and scale it for the removal of the inside…then add a Boolean Modifier…select shelf-cube and set the object as the second cube and use difference.
Thank you! This was a lot easier and I just learned something new 
