Angle trisection drawn through formula_25 to the semicircle, resulting in the intersection formula_28. The angle formula_48 generated by formula_49 and formula_50 is the angle formula_51 sought. Another means to trisect an arbitrary angle by a "small" step outside the Greek framework is via a ruler with two marks a set distance apart. The next construction is originally due to Archimedes, called a "Neusis construction", i.e., that uses tools other than an "un-marked" straightedge. The diagrams we use show this construction for an acute angle, but it indeed works for any angle up to 180 degrees. This requires three facts from geometry (at
The Three Degrees at The Royal Albert Hall" (aka "An Evening with The Three Degrees"), was recorded in October 1979 in which the trio were backed by the Royal Philharmonic Orchestra. In 1980, the compilation album "Gold" was released and became a UK Top 10 hit. Featuring one side of their hits on the Ariola label between 1978–79, and one side of live recordings from their 1979 Royal Albert Hall television special, this would be the trio's second "best of" compilation to make the UK Top 10 in less than two years, after CBS released "A Collection of their 20 Greatest Hits" in