Well, lets start with #3!
<1 is equivalent to <3 because they are vertical angles.
This means that <2 and <4 are congruent because they are vertical angles. We know that a straight line is 180 degrees. So, <1 and <2 added together will equal 180, therefore, <2 is ___________
Since the two lines are parallel, any angle on the other side is congruent, as long as that angle is in the same place as the other. So, we can see that <1 and <7 are in the same place, just moved down. So, <7 is __________.
