In ΔABC,
107° = x° + 57° (exterior angle property)
∴ x° = 107° – 57° =50° In ΔADC,
∠CAD + ∠ADC + ∠ACD = 180° (angle – sum property)
40° + 107°+ x°= 180°
∴ x° = 180° – 147° = 33°
Also in ΔABC,
∠A +∠B +∠C = 180°
40° + ∠B + (33° + 65°) = 180°
∠B + 138° = 180°
B = 180° – 138° = 42°
Now y° = ∠A + ∠B for ΔABC (exterior angle property)
=40° + 42° = 82°