Each triangle has an edge with 2 vertices and several intersection points. If you place numbers at the vertices and intersection points, each line will sum to 41.
Left upper triangle, starting from top vertex and going clockwise: 1, 14, 11, 2, 18, 17, 5. Right upper triangle, starting from top vertex and going clockwise: 16, 7, 8, 10, 11, 2, 14. Bottom central triangle, starting from top vertex and going clockwise: 14, 11, 15, 13, 4, 9, 2 Central, large, "upside down" triangle, starting from upper left vertex and going clockwise: 12, 5, 14, 7, 3, 8, 11, 13, 6, 4, 2, 17.
How many other solutions do the Durga Triangles have? No one knows.