Question

parallel lines s and t are cut by a transversal r.
which angles are alternate exterior angles?
$angle2$ and $angle8$
$angle4$ and $angle6$
$angle1$ and $angle5$
$angle1$ and $angle8$

Explanation:

Alternate exterior angles are angles that lie outside the two parallel lines, on opposite sides of the transversal.

• $\angle 2$ and $\angle 8$: $\angle 2$ is above line $s$ (outside the space between $s$ and $t$), $\angle 8$ is below line $t$ (outside the space between $s$ and $t$), and they are on opposite sides of transversal $r$. This fits the definition.
• $\angle 4$ and $\angle 6$ are alternate interior angles (between the two lines).
• $\angle 1$ and $\angle 5$ are corresponding angles.
• $\angle 1$ and $\angle 8$ are not alternate exterior angles (they are same-side exterior angles).

Answer:

$\boldsymbol{\angle 2 \text{ and } \angle 8}$