Ex 10.5, 4 - Chapter 10 Class 9 Circles
Last updated at March 2, 2017 by Teachoo
Transcript
Ex 10.5, 4 In the given figure, ∠ABC = 69°, ∠ACB = 31°, find ∠BDC. In ΔABC, ∠BAC + ∠ABC + ∠ACB = 180° ∠BAC + 69° + 31° = 180° ∠BAC + 100° = 180° ∠BAC = 180° − 100° ∠BAC = 80° For segment BADCB, ∠ BDC & ∠ BAC are angles in the same segment So, they must be equal ∴ ∠ BDC = ∠ BAC ⇒ ∠BDC = 80°
About the Author
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.