G being Geometry.
Euclid comes into that picture. Masonic tradition teachs that, Masonic tradition was in early history of the church of LDS, because of Joseph Smith Jr. and others...
LDS, "Mormon" was in EPS way of life. It becomes easier to understand where the UP came from, if you are aware of some history.
EPS put it into an outstanding way of easy recognition...
He did a fine job.