X57 I think no just doing this for points so made a random number lol
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
C.) 5, Using P.E.M.D.A.S you have to multiply first, so replacing the variable X with 5, it should look like this: (6*5) -3=27. 6*5 is 30, 30 subtracted by 3 is 27.