Answer:
about 50 degrees
Explanation:
To find the angle you would first subtract 180 - 90 (Since a triangle always equals 180) and that would be 90 and then divide by 2 to equal 45. I believe they wanted to round to nearest tenth so then the answer would change to 50. (Tell me if this is wrong; its been a while since I have done this)
I hope this helps :)