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 ...

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

👉 Learn about congruent triangles theorems. Two or more triangles (or polygons) are said to be congruent if they have the ...

Jeff Smith's Math Puzzle for April 10, 2026 - A Circle is ensnared within a right triangle – Call in the Jaws of Life. The ...

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 ...