Octadecagon and 2{9/4} or two enneagrams, {18/6} is reduced to 6{3} or 6 equilateral triangles, and finally {18/9} is reduced to 9{2} as nine digons. Deeper truncations of the regular enneagon and enneagrams can produce isogonal (vertex-transitive) intermediate octadecagram forms with equally spaced vertices and two edge lengths. Other truncations form double coverings: t{9/8}={18/8}=2{9/4}, t{9/4}={18/4}=2{9/2}, t{9/2}={18/2}=2{9}. The regular octadecagon is the Petrie polygon for a number of higher-dimensional polytopes, shown in these skew orthogonal projections from Coxeter planes: Octadecagon An octadecagon (or octakaidecagon) or 18-gon is an eighteen-sided polygon. A "regular octadecagon" has a Schläfli symbol {18} and can be constructed
How Many Clouds Can You See? How Many Clouds Can You See? How Many Clouds Can You See? is the second album by English saxophonist John Surman featuring Harry Beckett, Alan Skidmore, Barre Phillips and Tony Oxley recorded in 1970 and released on the Deram label. Allmusic awards the album 4 and a half stars and its review by Jason Ankeny states: "John Surman's second album remains his most impressive, anticipating the sound and scope of the European free jazz movement that would blossom in the decade to come". John Kelman in his All About Jazz review states: "While woodwind multi-instrumentalist John Surman's eponymous debut was