when it came time to build a pyramid out of plywood, I found myself stumped. This seemingly simple task is made extremely complicated by the compound angles of the mitered edges of each panel in the pyramid.
I eventually created a truncated pyramid with trapezoidal sides with base angles of 22.5 degrees, and edge miter angles of 40.2 degrees each. I couldn't see any rhyme or reason to the relationship between these two angles, so I looked online.
This explanation is a pretty good one.
But then I found this calculator, which is even better! (no math). but alas, it doesn't show the angles between the sides.
THEN, I found this gem of a site: the Miter saw calculator website, with calculators for all kinds of compound miter cuts.
I used it to predict the angles on my NEXT pyramid. Now, If I could only find tools accurate enough to make the cuts...