Skip to Content

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 …

Read More about Sankaku Puzzles

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… …

Read More about Tricky Triangles Puzzle

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 …

Read More about Triangular Turkey Puzzle

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 …

Read More about Three of Five Puzzle

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 …

Read More about SOH CAH TOA Notes

I am really excited about this shape grid puzzle from Erich Friedman. The goal of the puzzle is to divide the grid into geometric shapes. Any lines you draw must follow either the grid lines or the diagonals of the grid squares. Each shape that you draw must contain exactly one shape icon inside. This …

Read More about Shape Grid Puzzle

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. …

Read More about Trig Functions Posters

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 …

Read More about Pythagorean Theorem Poster

This equilateral triangle puzzle comes from Puzzle Box, Volume 1 from Dover Publications. This is the first book in a series of three puzzle books that are edited by the Peter and Serhiy Grabarchuk. This specific puzzle is by Richard Candy. Each volume has 300 puzzles, and I have found over a hundred puzzles between …

Read More about Equilateral Triangle Puzzle

Zukei puzzles are the brilliant creation of Naoki Inaba.  Inaba has posted these puzzles for free on his website, but it can be a bit hard to navigate since everything is written in Japanese. You may have heard of Inaba from his popular area maze puzzles. Instructions for Solving Zukei Puzzles The instructions for the …

Read More about Zukei Puzzles

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 …

Read More about Clinometer Activity and Foldable

I gave this missing angles task to my Trigonometry students as part of our beginning of year algebra and geometry review. I had students find the missing angles in this diagram that I found online.  Here’s a link the original source. Free Download of Missing Angles Task

Read More about Missing Angles Task