Page 1 - Lesson note-2 Angle subtended by Chord,Ch.- 10 Circle
P. 1

SAI International School
                                                           Class –IX


                                                       Mathematics





                 Chapter-10:  Circles                                       Lesson note-2

               Sub Topic:


               1. Angle Subtended by a Chord at a Point
               2.Perpendicular from the Centre to a Chord

               Theorem 10.1:
               Statement:  Equal chords of a circle subtend equal angles at the centre.

               Given:   AB and CD are chords of a circle with centre O, such that AB = CD.



















               To prove:  ∠AOB = ∠COD







               Proof:
               In ΔAOB and ΔCOD,

               AO = CO                [radii of same circle]
               BO = DO                [radii of same circle]
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