LESSON 01 · CLASS 9 MATHEMATICS (NCERT)

Chord & Perpendicular Theorems

Master chord properties: equal chords subtend equal angles at centre, perpendicular from centre bisects chord, and equal chords are equidistant from centre.

01 · CHORD THEOREMS

Core Chord Theorems

CIRCLE THEOREMS

Chords & Centre Distance

1. Theorem 9.1: Equal chords of a circle subtend equal angles at the centre.

2. Theorem 9.3: The perpendicular from the centre of a circle to a chord bisects the chord (OM ⊥ AB ⟹ AM = MB).

3. Theorem 9.6: Equal chords of a circle are equidistant from the centre.