Question

In figure, line segments AB and CD bisect each other at O. Identify the triangles which are congruent.

Answer 1

We have AO = BO.
And CO = DO
(AB and CD bisect each other at O)
$\text{Also}\angle AOC=\angle BOD$
$\text{Therefore by SAS congruence criterion,}△AOC\cong △BOD.$