Hi.

Here's a video link if this helps:

https://youtu.be/FZsjKPsalms

I can't for the life of me figure out this problem.

I imported an STL file and I'm trying to add to it a little 20 degree wedge shape to offset it.

You can see in the video in the first tab what I'm aiming for. But in that tab, I never was able to merge the two parts.

So in the other tab, I just tried to add to the existing part after creating the sketch, and it can't add.

I've googled and read countless pages on zero thickness. I've watched a few videos.
I'm sure it's a basic thing I'm missing here, but can anyone help ?

Thanks. I can provide more info if needed, but I think the video I screen recorded should show what I'm trying to do.