Answer:
42 deg, 138 deg
Step-by-step explanation:
Angles of a linear pair are supplementary. That means that their measures have a sum of 180 degrees.
Let the measure of one angle be x.
The other angle is 12° more than three times the first.
The other angle has measure 3x + 12.
The sum of their measures is 180 deg.
x + 3x + 12 = 180
4x + 12 = 180
4x = 168
x = 42
One angle measures 42 deg.
The other angle measures
3x + 12 = 3(42) + 12 = 138
The other angle measures 138 deg.