Touching triangles at their vertices

Question

What is the minimum number of non overlapping congruent triangles arranged in the plane,
such that each vertex of the triangles coincide with exactly three triangles?

Jaap Scherphuis · Accepted Answer

The number of triangles in my best solution is

but I don't know if this is optimal.

Addendum:
I previously had an incorrect solution, as I used similar triangles instead of congruent ones (i.e. I used some triangles of a different size but the same shape). As requested by @humn, I'll keep that incorrect solution with 12 triangles available below:

Amit Huda · Answer

suppose plan area is A and no of triangles are n,
A = n * 1/2 * h * b
so if we want n,
n = 2A /(hb), that is the minimum no of triangle

humn · Answer

A liberal interpretation of “coincides”
in the puzzle statement ...

“each vertex of the triangles
coincides with exactly three triangles”

... allows for a vertex to touch a side, and not always another vertex,
of another triangle as in these failed attempts ...

... that led to this pair of ...

Touching triangles at their vertices

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