http://www.hotwired.com/Ren2.0/Twain/Rim/cir_tri_sq.html (The Risc Disc Volume 2, 10/1995)
C I R C L E, T R I A N G L E, A N D S Q U A R E
In typical Zen fashion, the artist Sengai (1750-1838) never explained
the meaning of the three forms in his famous painting. Popular lore,
however, holds that they represent the material, mental, and spiritual
worlds.
