2 supplementary angles equal 180 degrees.
Let the asupplementary angle = X
Then from the problem the other angle = 3X-8 ( 3 times the supplementary angle minus 8)
So now you have X + 3X-8 = 180 degrees.
Combine the like terms:
4X -8 = 180
Add 8 to both sides:
4X = 188
Divide both sides by 4:
X = 188 / 4
X = 47 ( Supplementary angle).
The angle you want is 8 less than 3 times that:
3 *47 = 141 - 8 = 133 degrees