trisector

plural trisectors

1. geometryA line or curve that trisects something.

   Coordinate term: bisector

2. informalgeometrySomeone who believes to have found a way to construct an angle one-third the size of an arbitrary angle using only an unmarked straightedge and compass (this is known to be impossible; see Angle trisection § Proof of impossibility on WikipediaWikipedia ).

   1 more example

   A trisector is a person who has, he thinks, succeeded in dividing any angle into three equal parts using straightedge and compass alone. He comes when he sends you his trisection in the mail and asks your opinion, or (worse) calls you to discuss his work, or (worse still) shows up in person. You may think that the problem of how to deal with trisectors is not an important one; I intend to show that it is.

   1983, Underwood Dudley, “What To Do When the Trisector Comes”, in The Mathematical Intelligencer, volume 5, number 1, New York, N.Y.: Springer-Verlag New York, →ISSN, →OCLC, page 20, column 1