Don't think you are the first to choke on that one. LOL Some great writers have tangled with it. I believe they would be angles that reached out of this dimension into another intangible reality, if that helps.

The problem with Lovecraft being right is that if you know about them, they know about you. Azathoth sees all.

Its something almost specifically associated with Lovecraft.

I've seen this geometry, but I was out of my body on hydroponic mushrooms (no joke)

How to describe it though??

The angles were also curves?

The shapes weave and carve themselves out of nothing, and then back into nothing but it always somehow has a volume, area, perimeter...

Let me think about this for a second.

Nobody knows, it's impossible to imagine. That's the point. It's all fancy talk. To elaborate:

It's where geometry beyond human comprehension exists; angles intersect at impossible angles, and colours from outer space blend into shapes that are detrimental to your very sanity.

I think the closest possible analogue is to take 10 grams of shrooms and then smoke a fuckton of weed to land yourself in a bad trip with ego-death where you're falling through fractal patterns while losing all sensations of yourself. You will not know who 'you' are anymore, and feel like you are going insane with extreme fear, but you cannot even grasp the very concepts of fear or sanity; yet you realize something is terribly wrong.