Answer:
n = 15
Step-by-step explanation:
A straight line equals 180 degrees
Angle SWT is congruent to angle XWV meaning:
SWT (55 degrees) = XWV (55 degrees)
Set up an equation:
3n + 80 + 55 = 180
Combine like terms
3n + 135 = 180
Subtract both sides by 135 to isolate variable n
3n = 45
Divide both sides by 3 to isolate variable n
n = 15