Extend edges to intersect

I’m trying to re-model some fairly basic CAD data. I thought it would be pretty straight forward, but I’m lacking a technique to do it. Hoping you folks can help. I simplified all of the main faces. Everything was triangulated, and had tons of extra vertices. I figured I’d elminiate the bevels (called fillets in the CAD world), then redo the bevels in blender, probably as modifiers in case I need to change something.

I took a couple screen grabs of the most difficult part. I did one of the right angle sides, but this portion isn’t a right angle. And the sides are drafted, which also make this more difficult.

I could just go back and do it a different way. Realistically I have the CAD. I could just bring it into Fusion360 where you can select the edges, delete, and it does everything for you. But I’m trying to learn the technique in Blender.

So I have 2 questions here:
How do I close up those two thin vertical holes while keeping the face angles the same? Ideally they would meet at the corner point of the top surface.
Then, how to I extend the top edges of those buttom surfaces perpendicular to the face normals, hopefully all at the same time. In CAD we would call this, extend surface.

in blender, you can slide along edges, but that tool doesn’t project those edges past their end points.

I’m sure I’m just not thinking of a way to do it in blender because I keep thinking of the ways I would do it in Rhino.

I’m also wondering if this is pretty much exactly what Mesh Machine does? I wasn’t sure if it would work well on CAD mesh since it’s a mixed bag of quads and tris. But this particular problem might be unique anyway because the middle gap there had a bevel that meets exactly to the next surface. Blender doesn’t like those things usually. It’s right up there with hotlining. CAD usually doesn’t mind it. Blender hates it. But I was only going to bevel with a few subdivisions anyway, so no one would notice that I have the bevel Just short of that edge.

If you press G twice and then hold alt, you can slide extending past the end of an edge.

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:man_facepalming:
Thank you.

Any way to get these to intersect though? I would just extend one past first, then extend the other till it’s visually through the surface. Then back up the other till they are close enough.
Honestly, close enough is probably ok. But if there’s a way to be more precise I’d like to know it.

Select one of planes and use Intersect (Knife) command in Face Menu (Ctrl+F):

You can delete these 2 new faces afterwards.

If you have more than 2 faces you can do them all in one go, select all of them and change Source to Self Intersect:

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Aaaaa! A trim tool!
I didn’t know about that for sure.

That’s perfect. All I had to do was scale all of the surfaces based on surface center. Use this tool and delete the extra faces. Took all of 2 minutes to do the whole thing.

Thanks so much.
The other tip was also useful, as I didn’t know I could hold alt. I really need to look at the bar All the way at the bottom with tiny tiny text more often so I might notice if there are more options.