I suppose it’s fair to say that I don’t really love geometry. I mean, I find some of the topics interesting, but there are other topics that don’t do anything for me. Of course, you can’t let the students know which topics are which! But, between you and me, my favorite geometry topic has to be teaching students about parallel lines cut by a transversal. It’s probably because you can easily add algebra concepts to it, we get to color lots of angles, and it just makes sense to my pattern-seeking brain.
Now please, don’t tell my colleagues that I even admitted to liking anything that has geometry related to it. They know of my less than enthusiastic relationship with this branch of math. As far as interactive notebooks go, learning about transversals and parallel lines gives students lots of chances to interact with this concept. They get to do discovery activities and color coding. Let me break down what this looks like in my class’ interactive notebook.
Teaching using interactive notebooks
Interactive notebooks have so many advantages over other types of notes. In math we need students to interact with their notes and not just write down information. We use a variety of activities and graphic organizer to teach students the basics of parallel lines cut by a transversal line. Also, we learn about the interior and exterior angles of triangles. There’s 5 components in this unit that I’ll share with you below (to read more about the 5 types of components, check out this post.)
I can statements
We give students a list of I can statements to put in their notebooks to show them what objectives we’re targeting for this topic. This practice really sets the course for our learning journey. For this topic, students will learn about angles in triangles and with parallel lines cut by a transversal. When I created the I can statements I refered to the standards and then put the learning goals into kid friendly language.
With I Can Statements, students also get a chance to mark their progress. For example, once a student has shown that they can find the missing angle in a triangle, they put a check mark next to that. This also gives students a chance to talk about the misconceptions or difficulties they’re having. Maybe they’ll recognize that they mix-up interior and exterior angle relationships, for example.
Looking for more tips & tricks on implementing interactive notebooks and foldables in your classroom? You’ll want to check out this FREE mini-course on how to get the most out of interactive notebooks. It’s a 5 part series delivered right to your inbox. By the end, you’ll have your own customized plan for either starting, or ramping up, interactive notebooks in your class.
Building background through vocabulary discovery activities
To begin this unit on parallel lines cut by a transversal, we work on three introductory activities in our notebooks. The first one is a vocabulary activity. After that we complete two discovery based activities. These three activities give every student a similar background with the topic before we get into the nitty gritty.
Vocabulary activity
As students learn about angle relationships, they need to know some specific vocabulary. With my students I find this to be the hardest part of this unit. They struggle more with the words than the math. So, I make sure to spend extra time with the vocab. This notebook page introduces the vocabulary and gives students a visual representation of these terms. Throughout the rest of the unit we refer back to this page often when students forget what the words mean.
Discovering interior angles of triangles
I love discovery activities in math. Basically, it gives students a chance to find the patterns and make connections before someone tells them what to remember. I’ve found that discovery activities lead to better long term retention of concepts. In this activity students get a triangle on one piece of paper and they prove that the three angles in the triangle add up to 180 degrees. It’s a fast activity and it gives everyone a shared experience to refer back to when students need a reminder.
Discovering exterior angles of triangles
Similarly, students need to understand why the two interior angles of a triangle are equal in measurement to the exterior angle. For this background building activity students take a triangle and rip off the interior angles. This gets glued to fit the exterior angle. Using their observations, students then write a rule about exterior angle measurements in their own words. Students love these discovery activities. I like to include them in students’ notebooks to give them a clear visual to remember and refer back to.
Transversals notes and graphic organizer for the INB
After introducing the unit with I Can statements and background building activities, the next step is to put the notes into the notebook before we practice. Since they use the same vocabulary and basic background understandings, I introduce both angle relationships of triangles and transversals together. However, since they’re different major concepts, when it comes to formal instruction and notes, I do both the notes and practice for one of those concepts before moving on to the notes and practice for the other topic.
Color coding the angles when parallel lines are cut by a transversal
Many of the activities that I use with kids for this topic are similar to things you will find on Pinterest. Once I saw the color coding activities, I knew I had to do them with my students. After students have color coded angles created by a transversal and parallel lines you can have conversations with students about how the different colors are related. When discussing these angles, students can also refer back to their vocab notes and use the vocabulary from that page and use sentence stems. Here are some possible sentence stems students can use:
- Angles 1 and 4 are ________________ because _____________________.
- Two angles that are next to eachother like ____ and _____ are ______________ angles.
- The exterior angles are ____, ____, ____, and _____.
- Angle 4 is __________________ to angle 5.
I like toteach students to continue shading transversals during their practice and on tests. They can use their pencil lead for gray and then leave some white for the other color. This helps them to not make silly mistakes.
Color coding the angles when parallel lines are cut by a two transversals
I like to have students color code angles when parallel lines are cut by TWO transversals as a challenge for students. I want to see if they can figure it out on their own. They’ve already learned how the angle relationships work, so this is an opportunity to apply their understanding to a different situation. It’s helpful to let them talk to their partner and bounce ideas off of each other. After they have had a few minutes to think and talk about it they can share their thoughts with the class. This will give them an opportunity to do the thinking first, and then you can complete it as a class.
Angle relationships reasoning
The topic of angle relationships can be one of those times when the curse of knowledge kicks in for me as a teacher. Transversals make so much sense to me, but they aren’t always so intuitive for students. In this foldable students get a chance to find the measure of all of the angles and explain their reasoning. They have to use the words congruent and supplementary in their reasoning statements. This is one of my favorite foldables in our entire notebook.
Interior and exterior angles of triangles notes
Now that students have previously completed the discovery activity for interior and exterior angles of a triangle, it’s time to summarize what we learned in this foldable. Students have the opportunity to show and explain their finding for both interior and exterior angles of a triangle. This foldable notes page serves as a simple place for students to reference the rules that we discovered.
Guided practice problems
With this topic, I feel like students really have to learn when to make the connections and relationships between angles. They have to remember a few basic ideas about congruent angles, vertical angles, and supplementary angles and then apply them to novel situations. Working through example problems together in the notebook gets students started in using this new information to solve problems, and it becomes a great reference for them throughout the practice activities they do later in the unit.
As you can see below, in this practice activity students practice finding the missing angle when parallel lines are cut by a transversal, as well as angles of triangles. Working together through problems like these provides a great first taste to see how they’re understanding this topic. In the last problem they have to solve an equation to find x. I threw that in there to help them see that while they’re working with angles, they also need to apply math skills we’ve previously worked on, especially solving equations.
Cheat sheet for extra reference
The final page of notes for this unit is the “cheat sheet,” a quick page of important reminders for students. For this cheat sheet I wanted to make sure that they have a few simple reminders like “a straight line measures 180 degrees”. I work hard throughout the unit to ensure that students don’t just memorize steps. They remember things so much better if they understand what’s happening. This cheat sheet makes a great anticipatory set. Students can write questions from the information on the cheat sheet. Then, collect their questions and ask them to the class. A simple warm up like this just gets students thinking about the basics.
Let’s wrap it up
So, let’s get out there and teach the heck out of this topic. Transversals and angles of triangles is a fun topic to teach because it’s so visual and there are so many chances to get students talking about it. These notes work with my students because they really spice up the lesson and get students truly interacting with their interactive notes.
You can use the ideas above to bump up your interactive notes for your class, or you can grab the entire set of notes I use in my classroom in the “Transversals and Triangles Notebook Bundle.” If you’re looking for ideas for how to get students the practice they need with transversals and triangles, check out the post “12 Activities for Making Parallel Lines Cut by Transversals Memorable”.
