Respuesta :

Answer:

  • 180° - 1/2(α + β)

Step-by-step explanation:

The two angles of the triangle ADB are:

  • m∠A/2 and m∠B/2 or
  • α/2 and β/2

The three interior angles add to 180°, so the missing angle is:

  • m∠ADB = 180° - 1/2(α + β)