Please just put one question per post.
I will help you by displaying the first one properly.
You can make new posts for the other two.
All I have so far is that the angle is 45+Beta
Where beta is the middle size angle of the congruent triangles.
I have not worked out what the exact size of beta is.
1) That angle is 105º ( Tthis works with 30-60-90 triangles only )
I tried using 20-70-90 triangle, and the result was 108º, plus black (red) line doesn't bisect the top right angle.