Please help me solve this problem, thanks a lot

IDn = 54º (hopefully)

Step-by-step explanation:

Bm and Dn are parallels so they are complimentary. So in theory All angles should sum 180º because they are just angles of a distorted rectangle, but since 4x+10 is distorted the other way I'll have to subtract it, in theory it goes like this:

(3x-6) + (2x-4) - (4x+10) = 180

3x + 2x -4x = 6 + 4 -10 + 180

x = 180 ???

wait... it's the other way around:

4x+10 + 2x-4 + 3x-6 = 180

4x + 2x + 3x = -10 + 4 + 6 + 180

9x = 180

x = 180/9

x =  20

IDn = 3*20-6

IDn = 60-6

IDn = 54º

If the theory is right 4x+10 should be about 90º, let's check:

4*20+10 = 80+10 = 90 (aha!)

the correct answer is 5 6 and 7