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.

Math produces the solution and the rationale for it. It also reveals that other problems are, at heart, identical. Put balls of six different colors into a bag. Pull out three.

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 ...

So, as you can see, all the smaller triangles can combine to become bigger triangles, which is where the trick lies. If you count up every different triangle formed by the lines, you should get 24.

Can you use math to figure out the best way to cut a sandwich in half? Let's find out. We prove triangles are best using a surefire calculation of great, okay, and bad bites. Different kinds of ...