Perpendicular Bisector of Chord

Perpendicular Bisector of Chord

The perpendicular bisector of a chord will pass through the centre of the circle.

Conversely, when radius is perpendicular to a chord, the chord is bisected at the point of intersection.

Explore!

Use the applet below to explore the property of a Perpendicular Bisector of Chord.

Move points A and B to shift the chord AB.

Click on 'Show Proof' to view 2 congruent triangles.

Proofs

Given AM = BM, OMB OMA (By SSS Test) ∴ angle OMB = 90°.

Given angle OMB = 90°, OMB OMA (By RHS Test)AM = BM.