A linear pair is a set of adjacent angles whose noncommon sides are opposite rays. This means that the rays point in opposite directions forming a straight line. Examining the figure, we can see that ∠ 6 and ∠ 8 are both adjacent angles to ∠ 7. Let's mark the two pairs.
We can see that both pairs have noncommon sides that are opposite rays. Therefore, ∠ 6 and ∠ 7, and ∠ 7 and ∠ 8 are linear pairs.
