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WBBSEClass XMathematicsTheorem Related To Circle05 Mark2022 Easy

QQuestion

Prove that the perpendicular drawn to a chord which is not a diameter, from the center of the circle, bisects the chord.

Exam-ready answer • 05 Mark

Answer

Given : AB is a chord of the circle with its centre at O, which is not a diameter, and OD, is perpendicular on the chord AB.

To prove : OD, bisects the chord AB i.e., AD = DB.

Construction : O, A and O, B are joined.

Prove that the perpendicular drawn to a chord which is not a diameter, from the center of the circle, bisects the chord

Proof : In △ODA and △ODB,

∠ODA = ∠ODB (Each is right-angle)

OA = OB [radii of same circle] and

OD = OD (common side)

∴ △ODA ≅ △ODB [By R-H -S axiom of congruency]

∴ AD = DB [Corresponding sides of the congruent triangles] [proved]

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