Problem B. 4668. (November 2014)

B. 4668. A tetrahedron is said to be strange if the line segments connecting its vertices to the incentres of the opposite faces are concurrent. What condition is true for the edges of a strange tetrahedron?

Suggested by J. Ruff, Pécs

(6 pont)

Deadline expired on December 10, 2014.

Statistics:

32 students sent a solution.
6 points:	Andi Gabriel Brojbeanu, Baran Zsuzsanna, Fekete Panna, Geng Máté, Kátay Tamás, Kerekes Anna, Leitereg Miklós, Mócsy Miklós, Nagy Kartal, Nagy-György Pál, Nagy-György Zoltán, Schwarcz Tamás, Szebellédi Márton, Szőke Tamás, Török Tímea, Wei Cong Wu, Williams Kada.
5 points:	Bereczki Zoltán, Csépai András, Gáspár Attila, Gyulai-Nagy Szuzina, Porupsánszki István.
4 points:	9 students.
0 point:	1 student.

Problems in Mathematics of KöMaL, November 2014