Octadecagon 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 as a quasiregular truncated enneagon, t{9}, which alternates two types of edges. As 18 = 2 × 3, a regular octadecagon cannot be constructed using a compass and straightedge. However, it is constructible using neusis, or an angle trisection with a tomahawk. The following approximate construction is very similar to that of the enneagon, as an octadecagon can be constructed as a truncated enneagon. It is also feasible with exclusive use of compass and straightedge. The "regular
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