Building on young mathematicians' prior knowledge of three-sided shapes, this lesson plan series explores the defining characteristics of different types of triangles. Starting with a shared reading of the children's book The Greedy...

With so many different types of triangles, it can be a challenge for young mathematicians to keep them all straight. Luckily this set of printable triangles is here to engage children in comparing and sorting triangles by their...

Having a good working knowledge of math vocabulary is especially important for geometry learners. Here are 119 pages worth of wonderfully constructed definitions, constructions, formulas, properties, theorems, and postulates. This is a...