Question

In the figure OA = OB and OD = OC Show that

(a) $△AOD\cong △BOC$
(b) AD || BC

Answer 1

$In△AOD\&△BCO$

$=>OD=OC$ (given)

$OA=OB$(given)

$\angle AOD=\angle COB$ (vertically opposite)

$=>△AOD\cong △BOC$

$\angle OAD=\angle OBC$(angles corresponding to congruent sides)

$[\because$ AD & BC make equal angles with the same line AB]

$HenceAD||BC$