Hsjakakskskkskskd. because ypu never know athaysne s
The 3 inside angles need to equal 180.
Subtract E from 180 to find the sum of the other two angles:
180 - 104 = 76
Now because EF ≅ DE , angle D and F would be the same so divide 76 by 2
Angle D = 38
Equation C. :) lalalalalala