trihexaflexagon: clarify the formula in get_angle_in_plan_relative_to_hexagon()
-rw-r--r-- 32 .gitignore
-rw-r--r-- 455 Makefile
-rw-r--r-- 840 README.md
-rw-r--r-- 384 TODO
drwxr-xr-x - contrib
drwxr-xr-x - src