Theorem 10.4 : The line drawn through the centre of a circle to bisect a chord is perpendicular to the chord.

Explanation

In `/_\AOX` and `/_\BOX`

`OA=OB` (radius)

`OX=OX` (Common)

`AX=BX` (given)

By SSS congruency, `/_\AOX` and `/_\BOX` are congruent.

`/_AXO=/_BXO` (CPCT)
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In line `AB`,

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