The Total solution for NCERT class 6-12
(i) ∆ABD ≅ ∆BAC(ii) BD = AC(iii) ∠ABD = ∠ BAC
In quadrilateral ACBD, we have AD = BC and ∠ DAB = ∠ CBA
(i) In ∆ ABC and ∆ BAC,AD = BC (Given)∠DAB = ∠CBA (Given)AB = AB (Common)∴ ∆ ABD ≅ ∆BAC (By SAS congruence)
(ii) Since ∆ABD ≅ ∆BAC⇒ BD =AC [By C.P.C.T.]
(iii) Since ∆ABD ≅ ∆BAC⇒ ∠ABD = ∠BAC [By C.P.C.T.]