Theorems
Theorem 9.2 Important You are here
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 Deleted for CBSE Board 2025 Exams
Last updated at April 16, 2024 by Teachoo
Theorem 9.2 If the angles subtended by the chords of a circle at the center are equal, then the chords are equal. Given : A circle with center O. AB and CD are chords that subtend equal angles at center i.e. ∠AOB = ∠DOC To Prove : AB = CD Proof : In ΔAOB & ΔDOC OA = OD ∠AOB = ∠DOC OB = OC ∴ ∆AOB ≅ ∆ COD ∴ AB = CD Hence, Proved.