We spent forever arguing about the brain teaser that asks: How many triangles do you see? Here, mathematicians reveal the real answer. See if you’re right.

Discover the different types of triangles and find out the difference between an equilateral, scalene, isosceles and right-angled triangle in this KS2 guide.

If you did the math and your answer was 24, congratulations! You landed on the correct answer to how many triangles are in the puzzle—well, according to most people on the internet.

Big Idea – We can describe, measure, and compare spatial relationships. to build on students' knowledge of triangle and develop students' reasoning with properties of different classes of triangles to ...

A new proof breaks a decades-long drought of progress on the problem of estimating the size of triangles created by cramming points into a square. Consider a square with a bunch of points inside. Take ...

Jake Scott, also known as 2 Pi, is a math teacher at Montgomery Blair High School who engages his students by rapping about triangles and theorems. (Astrid Riecken/For The Washington Post) ...