Line-segment AB is parallel to another line-segment \(CD\). \(O\) is the mid-point of \(AD\).
 
YCIND_241124_6816_2.png
 
Show that
 
(i) \(∆AOB ≅ ∆DOC\)
 
(ii) \(O\) is also the mid-point of \(BC\).
 
Answer:
 
(i) Consider \(∆ AOB\) and \(∆ DOC\).
 
\(∠ ABO = ∠ DCO\) ( as \(AB \parallel CD\) and \(BC\) is the transversal)
 
\(∠ AOB = ∠ DOC\) ()
 
\(OA = OD\) (Given)
 
Therefore, \(∆AOB ≅ ∆DOC\) ()
 
 
(ii) \(OB = OC\) ()
 
So, \(O\) is the mid-point of \(BC\).
 
Hence, we proved.