Question

prove that equal chord of congruent circle subtend equal angle at the centre​

Answer 1

Given

In two congruent circles,

AB = CD

To prove

<AOB = <CO'D

Proof

In ∆AOB and ∆CO'D,

AO = CO' | Radii

BO = DO' | Radii

AB = CD | Equal chords

.°. ∆AOB = ∆CO'D | By SSS congruency rule

.°. <AOB = <CO'D | By CPCT

Hence, proved .