Answer:
Option (C)
Step-by-step explanation:
By the property of an exterior angle,
Exterior angle of a triangle is equal to the sum of two opposite interior angles.
(15x + 34)° = 29° + (12x + 26)°
15x + 34 = 29 + 12x + 26
15x - 12x = 55 - 34
3x = 21
x = 7
Measure of exterior angle = (15x + 34)°
= 15(7) + 34
= 105 + 34
= 139°
Option (C) is the answer.
