Any triangle we find in the drawing should have one top vertex and two others on the same horizontal line, so for each horizontal line, the number of triangles with two vertices on that line is ...

Join Mrs. Markavich for a number talk with D.C. as we work on decomposing and composing to make a 10. We'll also explore what makes a shape a triangle, a rectangle, or a square. Episode 403/1st Grade ...

Yet another viral math equation is taking over the internet. This time, it's a pink triangle within a square that has people scratching their heads. Can you solve it?

It’s shaped like a triangle on the number line. 8. In 1672, Gottfried Wilhelm Leibniz found a clever way to add the reciprocals of all the triangular numbers.