Show that if two chords of a circle bisect one another they must be diameters.

Explanation

Proof: In `triangleAOC` and `triangleBOD`

`angleAOC=angleBOD`

`OA=OB`

`OC=OD`

`triangleAOC~=triangleBOD` (By SAS)

Now, AC=BD ____1

In `triangleAOD` and `triangleBOC`

`angleAOD=angleBOC`

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