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  1. Chapter 10 Class 9 Circles
  2. Serial order wise


Theorem 10.1 Equal chords of a circle subtend equal angles at the center. Given: A circle with center O. AB and CD are equal chords of circle i.e. AB = CD To Prove : ∠AOB = ∠DOC Proof : In ΔAOB & ΔDOC AO = OD AB = CD OB = OC ∴ ∆AOB ≅ ∆ DOC ∴ ∠ AOB = ∠ DOC Hence, Proved.

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.