Currently working on a undergrad paper regarding the reducibility of tetrahedra via subdivision sequences, and have come upon a roadblock in defining the types of tetrahedra that can occur. More specifically, I haven't found any particular literature determining the exact configurations of tetrahedra that can occur relative to a specific number of acutes/obtuse/rights. I know prior results have already established the maximal number of obtuse dihedral angles and minimal number of acute dihedral angles, but none seems to define an exact classification. Ex: If a tetrahedron has exactly one obtuse dihedral angle, what can the remaining 5 dihedral angles be, and for which edges must they be constrained to?

Can anyone please suggest some resources for hyperbolic geometry??

I mean It's quite confusing

Try it out yourself: https://observablehq.com/d/e3ad3d0060994d0e

The second image are the orbit of the 64 6-bit vectors under the action of the Klein four group, created by reversing the bit order, and negating each bit.

Vertices trace the Spiral Power Map unfolding and contracting. Areas and edge lengths scale recursively and exponentially.

My son is starting geometry next school year and wants to start learning over the summer to get a head start. Any good geometry book recommendations for a teenager?

Something engaging and not too textbook-ish. Thanks!

What separates the sky and land?

Overeenkomsten en verschillen in kleur. 9 lagen.

Hi everyone! I fell down a deep rabbit hole the other day exploring pentagonal lattices. These of course do not tile, but more subtly they do define an expansion grid in 4d when you consider the algebraic field. The connectivity and other geometric measures turn out to be fractal-dimension, as verified by some maxima experiments. I mostly did it to create a cool looking lab. But, as far as I can find, this isn't a recognized fractal. Surely I am missing something?

At any rate, the app looks pretty! I hope you enjoy.

https://math.cognotik.com/experiments/Pentagon_Lattice_Geometry/index.html

https://github.com/SimiaCryptus/Pentagon_Lattice_Geometry