Interlocking forms

Interlocking forms - student project

Here are my own tries with this inspiring class. The instructions are great and it was easy to follow them. Though I have some problems with the triangles. If I try to separate the area via Pathfinder to then colour the lines, it gets another, smaller triangle or another form as you can see on my picture. Any ideas why this happens and how to change it? I do the same as with the letters.

Interlocking forms - image 1 - student project





#### Problem with triangles ####


Interlocking forms - image 2 - student project


Illustrator & Historian