You will do this assignment in pairs (NO MORE THAN 2). Each of you will do work on
your own piece of paper!
Given: a is parallel to b
Prove: 1  4
1. Study what is given and the diagram. Using postulates and theorems that you know, explain why
angle 1 is congruent to angle 4.
2. Using the strips of paper that you were given and your explanation in #1, arrange the two-column
proof for your problem. Once you think you’ve gotten it right, write your proof here:
Now try this one without the strips of paper! 
Given: a is parallel to b
Prove: 1 and 3 are supplementary
3. Study what is given and the diagram. Using postulates and theorems that you know, explain why
angle 1 is supplementary to angle 3.
4.
Using your explanation in #3 write a two-column proof for the problem.