Answer:
40
Step-by-step explanation:
In shapes with 4 angles, the angles must all add up to 360. So in this case we have 2 90 degree angles which added together equals 180, and an angle that is 140. If you add that together, you get 320. That is 40 less than 360. So that means that D is 40 degrees. Now looking at angle H, it looks the same as D, so I would say that H is also 40 degrees.
Hope this helps!