I have been doing a lot of research, not on sacred geometry but on the golden ratio. I am almost sad to admit my findings, but let my Luciferian side come out to accept what seems true. The first almost sad thing is how much merit this "sacred geometry" seems to have. First of all, the pattern now called "flower of life" is apparently found throughout the world and throughout time. Second, getting the platonic solids and all the other information that you can supposedly get out of it seems quite valid. Third, the new agers and theists have their hands all over the topic, ensuring it will likely never be taken seriously, which upsets me. However, I was looking into the golden ratio, as I said. The sad fact is that it's appearance and place in nature is greatly over exaggerated. Apparently it does not appear many placed. While it, and the Fibonacci sequence are quite beautiful, they seem to be created rather than discovered, unlike the rest of this theory. The pentagram may exist in nature such as tied to Venus, but it is really just a shape we made that has what we call the golden ratio (the golden pentagram specifically). The golden ratio is not found that often in nature, it was not used in all the buildings and art where it's use has been claim, and it does not make something more beautiful (beauty is completely subjective, and this has been tested). Sad to say, if there is something to "sacred geometry", Phi and the pentagram are likely not a part of it.
EDIT: Should be noted I mean the golden pentagram here. Pentagrams appear in "sacred geometry", but not golden ones.