Parallel Lines Proofs INB Pages

Parallel lines in geometry has the potential to be a fun unit! There are all kinds of activities on the internet with parallel lines and students are starting to become more comfortable with the vocabulary in geometry, so things get a little more relaxed. I've shared interactive notebook pages for parallel lines before, and they can be found here.

If you follow along with my personal life on Instagram, you'll know that I'm out of the classroom this year. I have a bunch of interactive notebook pages that I still need to share, but they are all from when I taught last year. Yeah, I'm that behind. Anyway, I figure it's better late than never!

These are not ALL of the interactive notebook pages that I use when I teach parallel lines. However, I didn't want to post a bunch of repeated, old stuff.  If you want to see the foldables that I've used for YEARS, you can check the link below.  They are time-tested foldables that are awesome!  Today, I wanted to share new stuff.  These foldables have either gotten a facelift or are totally new activities.

First, I teach students the location of alternate interior, alternate exterior, corresponding, and same-side (consecutive) interior angles and the congruence theorems that go with them. Once students are comfortable with the theorems, we do parallel lines proofs the next day. I used this parallel lines proofs booklet for students to organize their practice proofs and it fits in their interactive notebook. I have made the switch to having students write out most of the theorems in proofs, but they can get long so we wrote the "approved shorthand" at the top of the page. I made this switch because I felt like students were just throwing theorem names out there without even thinking about if it fit. This way, they at least have to think about what they are saying.

Then, I used an ugly foldable with diagrams copied and pasted from a textbook for the parallel lines converse theorems.  The proof booklet above has the types of proofs mixed together, so we go back and do all the proofs that we skipped the first day.  This lesson usually goes super fast because it's very similar to the lesson the day before.  I've shown a picture of my ugly foldable before, but at the top of this page, you can see the shorthand that I have my students use.

Once students have parallel lines proofs down, we move to writing equations of parallel and perpendicular lines. At both of the schools where I've taught, my students haven't learned equations of parallel and perpendicular lines in Algebra 1. So, it's always new information in Geometry and then a quick review in Algebra 2. First, I review slope and writing equations of lines. My first year I skipped the review and it was a mess. Don't skip the review. I use this flipbook every year. It's a quick review flipbook, definitely not for a beginning introduction of equations of lines.

Then, I use a time-tested foldable for equations of parallel and perpendicular lines you can find it through the link on the blog post below.  Students write the equations based on clues and they are organized under flaps.

Read:  Equations of Parallel and Perpendicular Lines INB Pages

Then, I created this new activity for students to practice telling if lines are parallel, perpendicular, or neither.  We looked at pairs of equations and then colored the box based on if they were parallel, perpendicular, or neither.  My students worked in partners and then we checked it together as a class.  When we checked, I had students vote and we only looked at the problems that had dissenting opinions.  It was better than doing every problem together.  This practice page can be found in this foldable.

I think these new foldables and activities were nice additions to my unit!