Question

AB and DC are two equal and parallel lines. Show that DA and CB are also equal and parallel.​

Answer 1

Kindly refer attachment

<AOB = < COD (Vertically opp. angle)

<OAB = <OCD (Alternate interior angle)

<OBA= <ODC (Alternate interior angle)

• AB = CD

So by ASA Congurancy triangle AOB is congruent to triangle COD

So OA = OC & OB = OD

And <AOD=<COB (Vertically opp: angle)

So by SAS Congurancy triangle AOB is congruent to triangle COB

So AD = BC - (1) also <ODA = <OBC & <OAD= <OCB

So if, Alternate interior angle of intersecting line (AC & BD) arc equal form AD & BC

which means lines are parallel AD ll BC

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