Respuesta :

unicorn3125

Answer:

          45° or 55°  {you didn't say which one is A}

Step-by-step explanation:

10x - 5° + 10x + 5° + 80° = 180°

20x = 100°

x = 5°

10x - 5° = 10×5° - 5° = 45°

10x + 5° = 10×5° + 5° = 55°