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Question
In the given circle with diameter AB, find the value of x.
Solution
∠ABD = ∠ACD = 30° ...[Angle in the same segment]
Now in ΔADB,
∠BAD + ∠ADB + ∠ABD = 180° ...[Angles of a triangle]
But, ∠ADB = 90° ...[Angle in a semi-circle]
∴ x + 90° + 30° = 180°
`=>` x + 120° = 180°
`=>` x = 180° – 120°
`=>` x = 60°
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