Me too and here is the breakdown. Lets define smallest possible triangle as Unit and so 1 Unit triangles = 16 4 Unit triangles = 7 9 Unit triangles = 3 All Unit triangles = 1

I missed on the 4 units ones, and I'd counted the big one Did not had time to reheck after shabbirs reply. Congrats Mridula :cheers:

1 2 3 4 5 6 7 8 9 a b c d e f The only possible points below which a 4-unit triangle can exist are 1 2 3 4 5 6. The only 4-unit triangle starting, e.g. at 7 is the one covering 7 4 8 2 5 9 which is the same as the one starting at 2.

Repost this time with code tags to preserve the formatting Code: 1 2 3 4 5 6 7 8 9 a b c d e f Oops no there is another one, sorry, 456 89 d. 27 it is then