Get the help you or your students need remembering all of the formulas needed for right triangle trigonometry problems with this handy right triangle trig formula sheet.

# Geometry Activities

Collection of Free Printable Activities and Resources for Teaching Geometry

This two-page set of notes has students compare two methods of finding the distance between two points on the coordinate plane: the pythagorean theorem and the distance formula. It is designed for Pre-Calculus students who have seen both methods taught in previous courses. In my many years of teaching pre-calculus, I have found that students …

It will be a few years before we get to celebrate the next Pythagorean Theorem Day in July of 2025. Here are some ideas for celebrating this fun mathematical holiday. For many, the Pythagorean theorem (also known as Pythagoras’ theorem) is one of the most memorable formulas from high school math. Most adults would likely …

Looking for fun and engaging geometry puzzles? Here is a collection of 25 free printable geometric puzzles that I have used in the past with my high school math students. Most of these puzzles should be appropriate to use with individuals ranging in age from upper elementary school or middle school to adults. My students’ …

Last year, I started my pre-calculus class off with geometry review. The first topic we tackled was finding missing angles in triangles. This set of notes was the perfect opportunity to pull out some of my favorite school supplies: colored pens and highlighters! The purpose of these notes was to review three key geometry concepts …

I use these classifying triangles by angles and sides notes with my pre-calculus students as part of our first unit of the year which covers mainly geometry review. Especially with the pandemic, I have to spend quite a bit of time reviewing geometry before we can jump properly into trigonometry. I have my students fill …

Sankaku puzzles are a geometric based logic puzzle that focuses on finding the area of a triangle. The goal of each puzzle is to connect three dots to form a triangle with the specified area. Sankaku puzzles are the creation of Naoki Inaba, a prolific Japanese puzzle creator. I first discovered these puzzles several years …

This tricky triangles puzzle has been around for over a century – can you arrange these eight sticks to form exactly four triangles and two squares? The original puzzle was meant to be solved with matchsticks, but I don’t think I need to explain why I won’t be giving my students matchsticks to play with… …

It’s November which means it’s finally time to pull out this Triangular Turkey puzzle for Thanksgiving. How many different triangles can you find in this picture of a Thanksgiving turkey? I ran across this triangular turkey puzzle in a Martin Gardner book (Perplexing Puzzles and Tantalizing Teasers) this summer, and I knew I had to …

I’m excited to get back to featuring a new puzzle of the week every week in my classroom this year. A new puzzle I have prepped for this year is called Three of Five. Three of these five figures fit together to create a triangle. Which ones are they? I ran across this puzzle in …