Hy!
I have a simple cylinder and I can’t select the smaller circle’s limited surface on its base. If I draw an identical circle then I can select but I don’t understand if the circle exist(I can select i the smaller circle!) then why can’t I select the area bounded by it?
cylinder.skp (43.2 KB)
How did you create all that in the first place?
The thick profile edges of the smaller circle are the clue that it does not divided the large face into inner and out regions. Tracing an edge segment with the Line tool fixes that.
I wanted to make my cylinder’s inside hole larger, so I made a larger circle and push it. Then I lost the surface of the top side and I had to recreate it. Now I need to delete the smaller circle on the top but is not accessible.
Please tell me what is the proper method to make the hole larger.
P.S How can I see better the thick profile edges of the smaller circle, because I don’t really see it? If you look at the end of my video you can see the smaller and the larger circle with the same thickness.
OK. So there are a couple of options. After you lost the top face, you could just use the Line tool to draw one or two edges between endpoints on the outer and inner circles. That would create the face between them without skinning over the opening. Tracing the edge segment on the outer circle tells SketchUp you want a face for the larger circle.
Another option, since the inner edges are identified as circles would have been to select one at a time and type the desired new radius in the Radius field of Entity Info.
If it’s too difficult on your display to differentiate between normal and Profile edges, go into the Style and edit the weight of the Profile edges to 3 or 4 maybe.
very nice solution! 
By to way when I made the circle with the desired diameter then pushed it, why did I loose the surface of the upper part, can’t I prevent this?
Delete the inner face of the 2D ring before extruding it to 3D.
Does not work.
.
In the original video why did I loose the surface of the upper part??
I did not tell you to delete the inner surface of the extruded cylinder.
From the extruded ring, delete the central hole before pushing through the new opening. In this case I double clicked on the inner surface to select the surface and its bounding edges, then pressed Delete.
