★ Solution:
Since it is given that the two angles are supplementary their sum must be equal to 180 degree
6x + 8 + 12x - 8 = 180°
→ 18x = 180°
→ x = 10°
Now substitute the value of x in the given two measures of angles.
- m∠ABC = 6x + 8 = 68°
- m∠DEF = 12x - 8 = 112°
Therefore the 2 angles are 68° and 112°
Hope it helps you :)