Question

identify all pairs of alternate interior angles
∠1 and ∠5
∠1 and ∠8
∠2 and ∠6
∠3 and ∠5
∠3 and ∠6
∠3 and ∠7
∠4 and ∠5
∠4 and ∠6
∠1 and ∠8

Explanation:

Step1: Recall alternate - interior angles definition

Alternate - interior angles are formed when a transversal intersects two parallel lines. They are on the interior of the two parallel lines and on opposite sides of the transversal.

Step2: Identify pairs

In the given figure, when two parallel lines are intersected by a transversal, the pairs of alternate - interior angles are $\angle3$ and $\angle5$, $\angle4$ and $\angle6$.

Answer:

$\angle3$ and $\angle5$, $\angle4$ and $\angle6$