Answer:
∠1 = 65
∠2 = 115
∠3 = 25
Step-by-step explanation:
Sum of angles in a triangle is 180.
40 + 75 + ∠1 = 180
115 + ∠1 = 180
∠1 = 180 - 115
∠1 = 65
∠1 and ∠2 are linear pair angles,
Sum of linear pair angles is 180
∠1 + ∠2 = 180
65 + ∠2 = 180
∠2 = 180 - 65
∠2 = 115
∠3 + ∠2 + 40 = 180
∠3 + ∠115 + 40 = 180
∠3 + 155 = 180
∠3 = 180 - 155
∠3 = 25
