Yes, it is credibly proven: in general, an exact tripartition of an angle, only with a compass, pen and unmarked ruler, is not possible. However, it can be an exciting task to find an approximation construction that has the smallest possible absolute error with relatively little effort.
Well, the question: Which approximation construction holds the record?
Here is an example of a approximation construction that has acceptable accuracy with relatively little effort: https://commons.wikimedia.org/wiki/File:01_Dreiteilung_des_Winkels-180%…

Yes, it is credibly proven: in general, an exact tripartition of an angle, only with a compass, pen and unmarked ruler, is not possible. However, it can be an exciting task to find an approximation construction that has the smallest possible absolute error with relatively little effort.

Well, the question: Which approximation construction holds the record?

Here is an example of a approximation construction that has acceptable accuracy with relatively little effort:

https://commons.wikimedia.org/wiki/File:01_Dreiteilung_des_Winkels-180%…