In ΔADC and ΔCBA,
AD = CB
(Opposite sides of a ||gm)
DC = BA
(Opposite sides of a ||gm)
AC = CA (Common)
Therefore,
ΔADC ≅ ΔCBA
( by SSS congruence rule.)
∠ ACD = ∠ CAB ……(i)
(by CPCT)
∠ BCA = ∠ CAD…..(ii)
(By CPCT)
& ∠ CAB = ∠ CAD…..(iii)
(Given)
From eq i,ii,iii,
All 4 above angles are equal to each other..
Hence, ∠ ACD = ∠ BCA
Thus, AC bisects ∠C also.