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
John H. Sides Burke summoned Sides, Freitag, and other Navy missile experts to his office for a briefing on the FBM research studies. By the end of the meeting, Burke had reversed Carney's veto and committed the Navy to an all-out FBM development program, directing Sides and Freitag to work out the operational details. Sides handled the Navy's side of negotiations over how exactly to implement the Killian Committee's recommendations, which called for the Navy to develop a ship-launched FBM similar to the Army's Jupiter IRBM. On September 13, 1955, President Dwight D. Eisenhower accepted the Killian Committee recommendations and directed the Navy