Exercise 1 Page 311

We are told that $m\angle 1=94^{\circ }.$ The task at hand is to find the measure of angle $\angle 3.$ We can use the given diagram as an aid to help us find those angles. Begin by highlighting each needed angle to stand out against the others.

These angles are formed by the parallel lines $m$ and $n,$ and the transversal $t.$ They both lie on the same side of the transversal and on the same left side of the parallel lines. According to the definition, these are called corresponding angles. Thus, to find the measure of $\angle 3,$ we can use Corresponding Angles Postulate.

According to the postulate, we can conclude that $\angle 1$ and $\angle 3$ are congruent. This means that their measures are the same. Therefore, the measure of $\angle 3$ is also $94^{\circ }.$