I just tested my students over parallel lines in Geometry and they did much better than I expected!  Their proof skills are improving so much.  
The first interactive notebook page for this unit was this graphic organizer from All Things Algebra.  I had students color-code the angle pairs and they also marked on their diagrams.
Next, I used my foldable for parallel line angle pair relationships.  Under each flap is a diagram with the definition, the theorem (congruent or supplementary) and an example.  I also had students write the theorems in shorthand under the foldable.  I do not allow students to write the theorem names when writing proofs, but I do allow them to use short hand.  This shorthand that I gave was the minimum amount they could write in a proof.
I created a hamburger book for practice with proofs.  I ended up doing some cut and paste with my proofs task cards to create this.  I want to create a better looking book (that faces the correct direction!) for next year.
I made the students actually write out the parallel lines converse theorems.  I think they needed the muscle memory.  I also allowed them to use the converse of the shorthand they used for the original theorems.  The little mini-book at the bottom has lots of copy and pasted diagrams inside (read: ugly) from their textbook with examples.
I created another proofs practice hamburger book for the proofs with the converse theorems.  I copied and pasted from my task cards.  Again, this needs beautifying for next year.  It also bugs me that they have to turn their books to read it.  I left tons of space on the side of the proof so students could write themselves hints.  They are starting to notice patterns in proofs and I wanted them to use this space to note that in their notebooks.
The next page has the perpendicular lines theorems.  In the past, I have also done proofs with the perpendicular lines theorems.  However, this year I made the executive decision that I wouldn’t include these theorems in their proofs.  It isn’t required in our standards, but I always included it for good measure.  I haven’t yet decided if leaving it out is a good move or a bad move.  The page is to be printed on legal or ledger paper and trimmed down to fit in their notebooks.  A friend has gotten me hooked to using the giant paper.  :)
 
 





