Yesterday I also got frustrated.
The few blue triangles I had cut out
kept falling off the wall as I moved them around.
And I didn't have enough of one color to make "cards"
and keep track of what I was trying to accomplish.
So I cut out 4 squares of paper for the 4 cards.
Then on each piece I made one slit half way down to the center.
I started at the middle of 1 side & stopped in the middle of the square.
This allowed me to fold under the hidden quarter for all the cards.
(It's easier for me to see the block as a "whole"
rather than a bunch of triangles.)
What I am working on above is distortion ...
the square cards are now rectangles.