Question

in the adjacent figure abc is isolates

Answer 1

First of all see what given in the question
AC=Ab (given)
AB=AB (COMMON LINE)
ANGLE D = ANGLE C
HENCE, TRIANGLE ABC congruent TRIANGLE ABD. by SAS criteria
BC =BD (C. P. C. T)

Answer 2

In ∆ABC & ∆ABD
AC = AD (Given)
<CAB = <DAB ( <A is bisected by AB)
AB = AB (Common)
therefore by SAS Congruency Rule
∆ABC =~ ∆ABD
BC=BAD (C.P.C.T)
hope it helps