I need help with angles on this joint

[exotic hound]

So I guess I'm not smart enough to figure out these angles, or rather to figure out how to cut them. I want to build something like this for a garden project. The instructions give me two specific angles for a miter saw (30°, 33.9°), but mine only has one adjustable angle (on the table). I should be able to adjust two angles on my table saw (blade and miter push thing). But I can't adjust them as finely as 33.9°...

I thought I could get away with adding a 30° angle on one end and screwing that to the side of the other board. But for reasons that I still can't figure out that doesn't yield a square...

I'm fine with a non fine woodworking solution, this is gonna get filled with dirt and grow strawberries, it'll have to take a beating.

This is what I'm trying to achieve (in approximation)

[oak marten]

I have linked something regarding compound angles on the wiki: https://wwwiki.org/en/technique/layout#splayed-miters-compound-angles; check https://woodgears.ca/miter/ and https://woodgears.ca/miter/splayed_miters.pdf. It's what makes "Trichterzinken" a bit of a challenge. I'm far from having fully grasped the issue. Meant to fully watch this one, since I think it covers it mostly: https://www.youtube.com/watch?v=r_k_alH8BO8

this one looks interesting as well, but you be the judge: https://www.youtube.com/watch?v=BjKDwxAOPiw

(looks a bit complicated, this "hack", but wdik)

[exotic hound]

Thx, I'll check that out. I'm hoping to do it with power tools, but maybe the theory is transferable

[ruby umbra]

Basically cutting crown molding if you need extra resources, lots of YouTube stuff on how to cut those. None I’ve seen with table saw tho.

[wispy raptor]

I have not tried this method myself but looks applicable https://www.finewoodworking.com/2002/10/01/compound-angles-without-math

[exotic hound]

Hmm I sadly can't read that, but thx

[muted junco]

Given that you're doing this in a relatively low-precision outdoor environment, you might be able to get away with just scribing it. Especially if you have a laser level. Angle board on the floor to aesthetically-pleasing tilt; use a square to get 45-degrees in the plane of the floor, and then transfer that line onto both exposed faces of the board. You might have to hand-cut it to be able to follow it without a power saw that can do compound angles, but as long as you somehow shape the wood to match the line, it should work