I added an image with the angles labeled so look at it first.
In the larger triangle, you know two angles, which means you can find the third one with the equation
20+40+x=180
60+x=180
x=120
Angle x is 120 degrees.
Since angle w is across from angle x, it is also 120 degrees.
Now we know two angles in the upper triangle, so we can find the third angle.
120+39+y=180
159+y=180
y=21
The ? Angle is 21 degrees.
Hope this helped!
