We know that angles in same segment are equal ∠ADB and ∠ACB are angles of same segment Thus, ∠ACB=∠ADB[∵∠ADB=300] (given) ∠ACB=300 ……(i) Angle of same segment are equal . ∠ACD and ∠DBA are angles of same segment. ∠ACD=∠DBA ∠ACD=600[∵∠DBA=600] …..(ii) x=∠ACB+∠ACD From equation (i) and (ii) x=300+600 x=900.