Supplementary angles add 180 degrees.
One of the two angles is 8 degrees more than 3 times the other.
If one of the angles is A and the other is B, then:

As they are supplementary, they add 180 degrees:

We replace the information of the second equation in the first one and solve:

Now we can solve for the other angle:

The measure of the angles is 34.4 degrees and 111.2 degrees.