In Fig. 10.7, if DAB = 60 �, ABD = 50 �, then ACB is equal to:

Given: DAB = 60°, ABD = 50°

Using the theorem “angles in the same segment of the circle are equal”:


ADB = ACB ……………… (1)


In triangle ABD, using the angle sum property of triangle, we have:


ABD + ADB +DAB = 180°


50° + ADB + 60° = 180°


ADB = 180° - 50° - 60°


ADB = 70°


From equation (1), we have:


ACB = 70°

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