Answer:
45
Step-by-step explanation:
You can use the degrees to find the answer. A right triangle always adds up to 180 degrees. The right angle is 90 degrees.
X + Angle A + Angle B = 180 degrees.
Substitute.
X + 90 degrees + 45 degrees = 180 degrees.
Add them up.
x + 135 degrees = 180 degrees.
now subtract 135 from both sides.
x = 45
