In the given figure, ∠ABC = 69°, ∠ACB = 31°, find ∠BDC. - Mathematics

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In the given figure, ∠ABC = 69°, ∠ACB = 31°, find ∠BDC.

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Solution

In ΔABC,

∠BAC + ∠ABC + ∠ACB = 180° (Angle sum property of a triangle)

⇒ ∠BAC + 69° + 31° = 180°

⇒ ∠BAC = 180° − 100º

⇒ ∠BAC = 80°

∠BDC = ∠BAC = 80° (Angles in the same segment of a circle are equal)

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Chapter 10: Circles - Exercise 10.5 [Page 185]

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NCERT Mathematics Class 9
Chapter 10 Circles
Exercise 10.5 | Q 4 | Page 185

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