Answer:
The angle is 141 degrees.
Step-by-step explanation:
We start by listing the angle as x.
Noting that, we know that it's supplement is 180 - x.
With these two facts given, we can model the equation as the following and then solve for x.
3(180 - x) - 100 = 17
540 - 3x - 100 = 17
440 - 3x = 17
-3x = -423
x = 141
