Q : 12 ABCD is a trapezium in which   and 
 (see Fig. 
). Show that diagonal AC 
 diagonal BD
[Hint : Extend AB and draw a line through C parallel to DA intersecting AB produced at E.]
  
 
                
                  Given: ABCD is a trapezium in which   and  
To prove: diagonal AC  diagonal BD
Proof: In  ,
BC=AD (Given )
AB=AB (Common )
      (proved in (i)  )
Thus,   (By SAS rule)
diagonal AC  diagonal BD    (CPCT)