Lets assume we are talking about small downward pointing equilateral

triangles.

There are n-rows of triangles.

The first contains 0 down pointers,

the second row contains 1 down pointer,

the third row contains 2 down pointer,

:

:

the i-th row contains i-1 down pointer,

:

:

the n-th row contains n-1 down pointer.

So there are:

RonL