Question

Two lines AB and CD intersect at O such that BC is equal and parallel to AD . Prove that the lines AB and CD bisect at O​

Answer 1

AS GIVEN A D IS EQUAL TO BC E SO THE ANGLE OPPOSITE TO THEM WILL ALSO BE EQUAL BY VERTICALLY OPPOSITE ANGLES

as a d and BC are parallel angle d and angle c will be equal as alternate angles

this prove that triangle ABC and ADO are congruent

so OA and Ob are equal by CPCT

So, line AB and CD bisect each other