Exercise 7 Page 181

Same-side interior angles are interior angles that lie on the same side of a transversal. From the diagram, we can see that $\angle 6$ and $\angle 8$ are same-side interior angles. They are formed by the lines $d$ and $e,$ and the transversal $c.$

There is only one more pair of same-side interior angles, $\angle 1$ and $\angle 2.$ This pair is formed by the lines $b$ and $c,$ and the transversal $d.$