Answer:
135°
Step-by-step explanation:
That triangle in the corner is an right angle isosceles triangle as that line the midpoint of both sides :
the base angle of this triangle (x) will be :
180 = 90 + 2x
90 = 2x
x= 45
Angles on a straight line add up to 180. So to work out a :
180 = 45 + a
135 = a
Hope this helped and brainliest please
