Everyone learns the number one rule about triangles in high school: the angles of a triangle add up to 180 degrees. But did you know that sometimes they don't? Triangles are much more interesting than ...

to build on students' knowledge of triangle and develop students' reasoning with properties of different classes of triangles to develop students' language related to different triangles to engage ...

Counting will get you nowhere. Try a little combinatorics instead. By Kenneth Chang A couple of weeks ago, I wrote about a viral math problem — 8÷2(2+2) = ? — that drew the disdain of many ...

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 ...