Accurately Rotate Triangles to meet at Top?

[RTCool]

BTW, it’s possible to create a tetrahedron without swinging an arc and hinging a face … but, if you want one face flat on the ground, you’ll still have to use the rotate tool to rotate the whole object over. See this post here:

Compound angle, 3 dimensional triangle

I learned a simple way to make a tetrahedron from Ann Tyng* by inscribing it in a cube. See this post I did back in 2017: A cube has six equal faces and a tetrahedron 6 equal edges, one for each face of a cube. [tetrahedron in cube 20210830] *Ann Tyng, was a classmate of my mother’s at Harvard Graduate School of Design, where they were among the first year of women to attend. Later she was a teacher of mine at U Penn. When you see things in Lou Kahn’s work like the tetrahedral ceiling of…