In a quadrilateral ABCD which is not a trapezium.It is known that <DAB=<ABC=60 DEGREE.moreover <CAB=<CBD.Then A) AB=BC+CD B) AB=AD+CD C) AB=BC+AD D) AB=AC+AD ? Choose correct option.

Option( c)is correct
i.e.AB=BC+AD
Given
##In quadrilateral ABCD /_DAB=/_ABC=60^@##
##/_CAB=/_CBD##
Construction
## BC and AD are produced to intersect at E##
## In Delta ABE/_EBA=/_EAB=60^@ =>/_BEA=60^@##
##:. Delta ABE is equilateral->AB=BE=EA##
Now
So option (c) is correct