Given: ∠DAB = 60° and ∠ABD = 50°

In ΔABD

By angle sum property

∠DAB + ∠ABD + ∠ADB = 180°

60° + 50° + ∠ADB = 180°

110° + ∠ADB = 180°

∠ADB = 180° – 110° = 70°

Here,

∠ADB = ∠ACB = 70° (angles in same segment)

∴∠ACB = 70°