Question 483998
The major problem with this is to avoid counting a triangle twice.
Each edge has a small triangle with no cross lines: 5
Each vertex has a small triange with no cross lines: 5
Each edge has 2 triangles with 1 cross line (its small triagle merged with one of the small triagles of its 2 vertices): 10
Each vertex (using its 2 original edges) has a triangle with 2 cross lines: 5
Each original edge to the opposite vertex has a triangle with 5 little cross lines: 5
Total = 30.
The previously posted solution counted the small triangle by an edge twice, hence over by 5.