21 trunks form a triangle 6x6 m, 5x5...
21 trunks form a triangle 6x6 m, 5x5...
21 trunks form a triangle 6x6 m, 5x5...
21 trunks form a triangle 6x6 m, 5x5...
21 trunks form a triangle 6x6 m, 5x5...
21 trunks form a triangle 6x6 m, 5x5...
21 trunks form a triangle 6x6 m, 5x5...
Morgenstern