The Golden Ratio is discussed at this site:
http://www.geom.uiuc.edu/~demo5337/s97b/art.htm
The Golden Section in Nature is discussed at this site:
https://www.goldennumber.net/nature/
There are many sites that discuss the relationship between math and art (that is between perspective and projective geometry). You need to look at sites that are not heavily weighted by mathematical notation. One such site is:
http://mathforum.org/sum95/math_and/perspective/perspect.html
This site explores Saccheri’s quadrilateral:
https://en.wikipedia.org/wiki/Saccheri_quadrilateral