I could probably substitute and simplify given time...but when Excel is so easy...the answer should anyone ever need it, is 52.62263 degrees and as I suspected does not vary with the length of the triangular faces.
As is often the case...I get stuck, post for help...then get lucky!
I've found the formula for the "slant height" (a term I did not previously know) which is the length of the bisecting line down the midpoint of the face.
Since I already have the formula for the height of the pyramid, I...
MY apologies that I don't think this is particularly advanced; my algebra and trigonometry is quite good, but all seems to fall apart once i move from 2D to 3D environments.
Johnson Solid J2 is a pentagonal pyramid consisting of five equilateral triangles on a pentagonal pase, meeting at the...