In quadrilateral ACBD,

AC = AD and AB bisects A (see Fig. 7.16). Show that Δ ABC Δ ABD.


What can you say about BC and BD?


It is given in the question that:

AC = AD and,


AB bisects A


To prove:


Proof: In


AB = AB (Common)


AC = AD (Given)


CAB = DAB (AB is bisector)


Therefore,


By SAS congruence,



BC and BD are of equal length


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