You are here
Theorem 2
Last updated at May 26, 2026 by Teachoo
Class 9
Chapter 5 Class 9 - I’m Up and Down, and Round and Round (Ganita Manja
- Definitions
- Symmetries of Circle
- Number of Circles
- Exercise Set 5.1
- Think, Draw and Infer (Page 98)
- Angle Subtended by Chords
- Exercise Set 5.2
- Mid-points and Perpendicular Bisectors of Chords
- Exercise Set 5.3
- Distance of Chords from the Centre
- Exercise Set 5.4
- Distance of unequal chords from center
- Exercise Set 5.5
- Angle subtended by an arc
- Exercise Set 5.6
- Concyclicity of Points and Cyclic Quadrilateral
-
Theorems (and their Proofs)
- End-of-Chapter Exercises
Transcript
Theorem 2 Equal chords of a circle subtend equal angles at the centre of the circle Given: AB & 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 Thus, by Corresponding parts of Congruent Triangles (CPCT) ∠ AOB = ∠ DOC Hence proved
