Answer:
See below
Step-by-step explanation:
Statement | Reason
1. m∠A + m∠B + m∠C = 180° | 1. Angles in a triangle sum to 180°
2. 28° + x - 4° + 2x = 180° | 2. Substitution
3. x=(180° - 24°)/3= 156°/3°= 52° | 3. Algebra
