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
How to Have Sex in an Epidemic How to Have Sex in an Epidemic How to Have Sex in an Epidemic: One Approach is a 1983 nonfiction manual by Richard Berkowitz and Michael Callen, under the direction of Joseph Sonnabend, to advise men who have sex with men (MSM) about how to avoid contracting the infecting agent which causes AIDS. It was among the first publications to recommend the use of condoms to prevent the transmission of STDs in men having sex with men, and has even been named, along with "Play Fair!," as one of the foundational publications in the advent of modern safe sex. The