Q4 of 141 Page 464

In the given figure, ∠DAB = 60° and ∠ABD = 50°, then ∠ACB = ?

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°

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