Following a well-designed trail of clues leads to...
Stay tuned for play-byThat trail begins at the two division / triangles
that both include the given 3
and must each include consecutive numbers.
The only possibilities are {2,3,6} and {3,4,12},
which fairly rapidly sift to:
• Use up 5 of the 7 available even numbers.
• Force a pattern of odd and even numbers among the remaining cells.
The 2 remaining even numbers fit only one way and:
• Daisy-play pictureschain upward to fill out all but the bottom row.
• Leave a set of numbers with only one pair that can
produce consecutive numbers in the bottom right triangle.
The bottom left corner shakes out from there. (And, yeah, the original path to solution involved some unnecessary trial and error.)