Whew...That was work!
Here is the triangle motif.
But, goodness...it wasn't easy. I now realize the two joins to the longer thread give it a bit of substance. Zoom in and you'll see the difference between the top one and the bottom two. I 'got it' after the first one. The second two seem to be correct.
Tatting several of the projects in the Blomqvist and Persson book I have to flip the piece and join...then, flip back. I also had to do the shoe string trick on each repeat. Additionally, the pattern does not + after the chains...but I did. Not sure this was correct but I'm really happy with the final outcome.
Your help was invaluable!
Hoping your day is wonderful!!