Answer:
Option B and C are the correct option.
Step-by-step explanation:
To solve this question we will go through each option given.
Option A. since ∠1 and angle = 100° are supplementary to each other.
∠1 + 100° = 180°
∠1 = 180 - 100
∠1 = 80° ≠ 100° Incorrect option
Option B.
∠3 and angle = 100° are supplementary angles
∠3 + 100 = 180°
∠3 = 180 - 100
∠3 = 80° Correct option
Option C.
∠3 and ∠1 are opposite angles
Therefore, ∠3 = ∠1 Correct option
Option D.
∠2 and angle = 100° are oppsite angles
Therefore, ∠2 = 100° ≠ 80° Incorrect option
Option B and C are the correct option.