Start by finding the interior angles based on the two given angle measures:
121 + x = 180
x = 59 (subtract 121 from both sides)
so the interior angle at the top is 59
144 + y = 180
y = 36 (subtract 144 from both sides)
so the interior angle on the right is 36
Now, all three angles of a triangle must have a sum of 180, so
x + y + z = 180
59 + 36 + z = 180 (substitute the two interior angle measures into the equation)
95 + z = 180 (simplify the equation)
z = 85 (subtract 95 from both sides)
Now that we know the interior adjacent angle is 85, we can find the exterior angle (n)
n + 85 = 180
n = 95 (subtract 85 from both sides)
so, n= 95 degrees