Given,
∠ACD = 105°
∠EAF = 45°
∠EAF = ∠BAC (Vertically opposite angle)
∠BAC = 45°
∠ACD + ∠ACB = 180°(Linear pair)
105° + ∠ACB = 180°
∠ACB = 180° – 105°
= 75°
In ΔABC
∠BAC + ∠ABC + ∠ACB = 180°
45° + ∠ABC + 75° = 180°
∠ABC = 180° – 120°
= 60°
Thus, all three angles of a triangle are 45°, 60° and 75°