Theorems
Theorem 9.2 Important
Theorem 9.3 Important
Theorem 9.4
Theorem 9.5 Important
Theorem 9.6
Theorem 9.7 Important
Theorem 9.8
Theorem 9.9 Important
Theorem 9.10
Theorem 9.11 Important
Angle in a semicircle is a right angle Important
Only 1 circle passing through 3 non-collinear points
Last updated at Dec. 16, 2024 by Teachoo
Theorem 9.1 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.