Answer: x= 45 degrees
Step-by-step explanation: The angle of a square is 90 degrees and it already tell you the other side is 45 degree so 90 - 45 = 45. So that means the answer is 45 degrees.
Since the sum of all the angles of any triangle is 180 degrees, just add 90 and 45 (the answer being 135), then subtract 135 from 180 (answer is 45).
Therefore, the missing answer is 45 degrees.