
I didn't know how to describe my problem in the title, so I'll try to do it here. Below I have a project. I needed to take a small piece from the middle of the object, and I couldn't get sculping to work, so I just used knife tool and excruded after I had created what I wanted.
Now, when I'm finally rendering, I'm getting unwanted things on the render result, caused by these extra verticles. Is it possible to remove them? I tried making the holes new objects, but that didn't really work.
Oh and, with 'verticle', I'm refering to the line that connects the hole into the rest of the object.
http://www.filedropper.com/blend1 (a link to the blendfile)

Just the two lines that are going out from the hole towards the body.
Oh and this is just a school project where I need to show rendered pictures, so if somebody has an idea how to fix the crappyness in rendering by changing texture mapping or whatnot, I'm fine with that, too.
– user3553653 Nov 13 '17 at 12:55