All angles in a triangle measures 180 degrees 
Add all the angles in triangle 2 
84 + 36 = 120 
The angle that is divided between triangle 1 and 2 measures 90 degrees so we are gonna add it to the total of triangle 2
120 + 90 = 210 
Because no angles in a triangle measures 210 we are gonna subtract 180 from . 
210 - 180 = 30 
The missing angle in the second triangle is; 
180 - 120 = 60 degrees 
The total we got after subtracting 180 from 210 is the missing angle for the divided side of triangle 1. 
Now that we have 2 angles we can now find “?”
To find “?” we are gonna add the two angles we have and subtract it from 180. 
86 + 30 = 116
180 - 116 = 64 
Therefore “?” is equal to 64 degrees.