A geometric problem which is easy to discribe but not to solve algebraically.
It was published first in Finnish 2013 in the magazine Dimensio, vol. 77 (2013), no. 2, p. 67.
The solutions dissappeared from the net 2017, when the publisher reformed its site totally.
The solutions will be collated here bit by bit.
At the same time, this is a trial to learn to create the first Geogebra book of my own.