We see that 22 and 23 are corresponding angles. And since the lines u and y are parallel, 22 and 23 are congruent. So, m3 = 150 °. We see that 21 and 22 are corresponding angles. Thus, 21 and 22 are congruent. So, mZ1 = Therefore, 21 and 23 are Choose one We also see that 2 1 and 2 3 are Choose one The relationship between 21 and 23 is an example of the following rule. When parallel lines are cut by a transversal, Choose one Continue