Here are a few reasons:
The triangles have the same three sides
The triangles have the same three angles
The triangles could perfect overlap one another
They have corresponding angles.
Not sure if this helped but I hope so!
I believe it would be any number that is within the darkest shaded area. (-4,1) seems like it would be correct.
Answer:

Step-by-step explanation:
There are no fractions I am assuming the fraction is 88/25 which would be 88/5^2
Answer:
64 degrees
Step-by-step explanation: