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.

# Right Triangles

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 …

I created these SOH CAH TOA notes for my Pre-Calculus students a few years ago to review how to find the trigonometric functions of an angle, given a triangle. First, we reviewed the different parts of a right triangle. I have also created a poster of the parts of a right triangle that might be …

Looking for a challenge? Check out this page of Make It Pythagorean Puzzles. Insert the same digit (in any manner of your choosing) to each side of the triangle to form a right triangle. I ran across these interesting puzzles in Golf on the Moon by Dick Hess (Dover Publications).

I created these trig functions posters a few years ago when I was teaching a year-long trigonometry course. Somehow, they never got a blog post of their own. I created separate posters for the three basic trig functions and the three reciprocal trig functions. I designed these posters to print on 11 x 17 cardstock. …

I created this Parts of a Right Triangle poster several years ago when I was teaching trigonometry. I wanted to emphasize the vocabulary words for adjacent, opposite, and hypotenuse before we jumped into right triangle trig. I designed this parts of a right triangle poster to print on 11 x 17 cardstock. I hung this …

I want to share a pythagorean theorem poster I created several years ago for my classroom when I was teaching trigonometry. I designed this poster to print on 11 x 17 cardstock. I hung this poster on a bulletin board in my classroom with several other 11 x 17 posters I created. As I continue …

I love this clinometer activity for giving my trigonometry students extra practice finding missing angles and sides of right triangles. Plus, it answers the question of “When will we ever use this?” I printed a clinometer template off of VirtualMaths.org for them to use. I mistakenly assumed that they would be able to put together …

I created this finding missing angles of right triangles practice book for my trigonometry students to glue in their interactive notebooks. My students were a bit miffed that they had to just write these equations. They thought I should have given them a foldable for these! I did make them a practice book, though. These …

We created this parts of a right triangle interactive notebook page to start off our unit on right triangle trigonometry. Each student had to cut a right triangle out of colored paper and glue it into their notebooks. We labeled one of the non-90 degree angles as theta. Then, we discussed how to identify the …

To give my students a bit more practice with word problems, I typed up these Romeo and Juliet themed pythagorean theorem problems. These are slightly modified from this Weebly site. Free Download of Romeo and Juliet Pythagorean Theorem Questions

I decided my students needed a Pythagorean Triples reference page in their notebooks to go along with the posters I have hanging in my classroom. Here is the page. You will notice that 6, 8, 10 is not included on the list because it is related to 3, 4, 5. Free Download of Pythagorean …

I created this practice book to give my trigonometry students some much needed review of finding the distance between any two points on the coordinate plane. I’m a rebel and chose not to teach the distance formula since it’s way easier to just use the Pythagorean Theorem instead. Instructions for Finding the Distance Between Any …

I used this One Big Square Task with my trigonometry students to review 45-45-90 special right triangles. I found this task in the Open Curriculum Task Database. I loved listening to the conversations my students had as they struggled through this problem. And, I mean “struggle” in the best possible way! Free Download of One …

I found this dragon puzzle to practice special right triangles online, and I fell in love with it. Each of the triangles is a special right triangle. I did a bit of research, and I was able to find the original source. I also found the same problem in McDougal Littell’s Geometry: An Integrated …

I created this special right triangle discovery activity to help my trigonometry students discover (or rediscover) the patterns in the sides of the 30-60-90 and 45-45-90 special right triangles. 45-45-90 Special Right Triangle Discovery Activity The page I’m showing you FIRST is actually what we did LAST. Yes, I’m that teacher who makes my students …

Since I’m teaching trig this year, I wanted to create some special right triangles posters to jog my students’ memories. Special right triangles are a topic they study in geometry but have often forgotten by the time they end up in my trig class. I designed the title to print on 8.5″ x 11″ and …

I created this set of free printable pythagorean triple posters to help decorate my new classroom. I’m teaching Algebra 1, Trig, and Math Concepts (a class for 9th graders not yet ready for Algebra 1) this year. As I was making a list of things my trig students need to review at the beginning …

SOH CAH TOA. The mnemonic device that sums up the majority of the population’s knowledge of right triangle trigonometry. Today I want to share a free download of a SOHCAHTOA Poster I made for my own classroom. Yesterday, I printed off a heap of posters and started laminating them. Earlier this summer, I had …

I’m excited to share my student’s creative wheel of theodorus projects which I turned into a Wheel of Theodorus Bulletin Board to decorate my high school math classroom. Every year, I have this plan to change my bulletin boards out throughout the school year. This year that happened only once. It also happened way back …

I learned about the song Gettin’ Triggy Wit It by WSHS on YouTube from Meg Craig. It was the perfect addition to our unit on right triangle trigonometry. If you haven’t seen this video, stop everything and watch it now. My students enjoyed the video the first time we watched it, but they had a …

I created this SOH CAH TOA foldable for my trigonometry students to glue in their interactive notebooks. Our geometry standards include basic right triangle trig, but I’ve found that my students’ experience with this topic is greatly lacking. They remember learning SOH CAH TOA, but they never really did know what they were doing. It’s …

These are the pythagorean theorem notes I used with my trigonometry students in our beginning of year geometry review. We glued these notes in our trigonometry interactive notebooks. The Pythagorean Theorem booklet was stole from the blog of Jessie Hester. She has a ton of resources for teaching the Pythagorean Theorem! If I was teaching …

I created this special right triangles practice book for my trigonometry students to glue in their interactive notebooks as part of our beginning of the year geometry review. This was our last topic to review before delving into actual trigonometry. I don’t know exactly what it is about special right triangles, but I LOVE them. …