April wrote: Some polygon can be divided into two equal parts by three different ways. Is it certainly valid that this polygon has an axis or a center of symmetry? Oh, very nice! I am the author of this problem! I do know only one example. If you have found another, please, write me. Thank you! Sergey Markelov

Hi Sergey, Nice to know you.

What do you mean that the polygon can be divided into two equal parts? Do you mean congruent parts or equal areas? What do you mean by different ways? Divided by a line in different ways, or some other way? It is known that given any direction, there exists a line parallel to this direction which cuts the polygon into two eqal parts. Therefore, please be more explicit in the statement of the problem.