2026 BTC Conference — New Haven: Presentation Slides
It was so nice to meet so many of you in New Haven. Thank you for your attendance, your participation, and your enthusiasm for the ideas we shared. The conversations we had were easily the best part of the conference for us. We genuinely hope you'll keep in touch and collaborate with us to keep improving these materials; they're better every time another teacher puts them to work and tells us what they found.
As requested, you'll find the links to our presentation slides below.
— Jill, Leah, and Jay
Thinking Through Geometry
A free, complete high school geometry curriculum built on Building Thinking Classrooms principles.
Geometry may be the only required high school course where students can experience the felt need for deductive proof from the inside, not as an imposition, but as the natural answer to a question they are already asking. This curriculum is designed to make that happen.
Why This Curriculum
- Built specifically for high school geometry teachers transitioning to Building Thinking Classrooms.
- A complete course, not a collection of tasks.
- Focuses on problem-solving habits of mind, not just rote memorization.
- Complete sequence of lessons, thinking tasks, CYU problems and curated note sheets.
- Designed to foster deductive reasoning and student agency.
- Proof and reasoning returned to the center.
- Free to use, share, and adapt for non-commercial educational purposes.
- Built by teachers, for teachers.
- Every lesson was taught, reflected on, and revised. The teacher notes include what actually happened: what worked, what didn't, and what changed for next time.
An Honest Note
The materials provided represent a way of doing things, not the way. They reflect the hard work, missteps, and small wins of a geometry teacher making sense of how to teach for thinking.
I want to be upfront: this curriculum does not perfectly align with everything Peter Liljedahl calls for in Building Thinking Classrooms. It is my best attempt to build a full, coherent geometry course on the BTC framework, but I made deliberate choices about where to deviate.
Liljedahl recommends against pre-printed problem sets and note sheets and for good reason. Pre-printed materials can reduce cognitive demand and pull students out of the thinking process and become something they just "need to complete". In this curriculum, I chose to pre-print the CYU problem sets because the material benefits from carefully sequenced, spiraled problems that align to navigation instrument rows. I found this works better for geometry than generating problems on the fly. The student note sheets are provided to ensure that everything intended in the curriculum gets covered during consolidation, however, they are not necessary to print or use. They are a safety net, not a requirement.
Nothing in these materials replaces the teacher's judgment in the moment. The thinking tasks, the consolidation, the pacing, those are where your responsiveness to your students matters most. The structure is the starting point, not the ceiling.
As you use these, keep what works, fix what doesn't, and always prioritize the thinking happening in front of you.
Read both of Liljedahl's books: Building Thinking Classrooms in Mathematics and Mathematics Tasks for the Thinking Classrooms. This curriculum assumes familiarity with the BTC framework. The books give you the pedagogical foundation; these materials give you the geometry content built on top of it.
Navigation instruments
Students receive their navigation instrument at the beginning of each unit and update it after every CYU. The instrument is not a grade tracker, it is a self-assessment tool. Students should revisit rows regularly, even rows they have already demonstrated understanding on. If they haven't yet reached their target level on a row, they should be working on that row every day.
The consolidation is where your professional judgment matters most. The teacher reference pages suggest what to consolidate and in what order but you know your students. Make daily decisions about what to name, what to leave open, and when to push deeper. The structure is here to support your teaching, not to replace it.
How to Use These Materials
Before you begin
Adapt freely
About This Project
The Thinking Through Geometry curriculum is the culmination of a Christa McAuliffe Sabbatical Grant, awarded by the New Hampshire Charitable Foundation, dedicated to redefining how high school geometry is taught. Rooted in Peter Liljedahl's Building Thinking Classrooms (BTC) framework, these materials transition geometry from a series of memorized formulas into a vibrant landscape of inquiry, reasoning, and collaborative proof. Epistemology becomes more important than a single fact about a shape. This project aims to empower teachers with the tools necessary to foster a classroom culture where students are the primary source of mathematical thought.
The daily flow
Each lesson is built around a thinking task that students work on in visibly random groups at vertical non-permanent surfaces. The teacher reference page for each lesson includes the task, what to watch for during circulation, and options for consolidation.
After the thinking task for consolidation, I prioritize notes. When time and content allow, I use a making-meaningful-notes approach where students construct their own notes at the boards from prompts, then transfer to paper. When time is tight, students take notes directly from the consolidation using the provided note sheets. Liljedahl's secondary task book has excellent guidance on the making-meaningful-notes practice. I recommend reading that section carefully.
After notes, I distribute the CYU (Check Your Understanding) problem set. Students work on it for the remaining class time, or it goes home. CYU sets include problems spanning all navigation instrument rows covered so far, with spiraled problems from earlier in the unit
An Invitation
This project is better when more teachers are part of it. If you use these materials, even one lesson, I want to hear about it. What worked? What didn't? What did your students do that surprised you?
If you have feedback, suggestions, corrections, or just want to talk about teaching geometry with BTC, reach out:
jay@thinkingthroughgeometry.net
This is a living curriculum. Every teacher who uses it and shares what they learn makes it better for the next one.
Free to Use and Share
All materials on this site are licensed under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0). In plain language: you are free to use, copy, and adapt anything here for your classroom. Share it with colleagues. Modify it to fit your students. The only restrictions are that you credit the source, don't sell it, and share any adaptations under the same license.
No login. No paywall. No catch.