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 ...

Well, what is the best way to cut a sandwich in half? Surely triangles don't really have "more sandwich," right? That's geometry and the law of conservation of matter. But something about the ...

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 ...

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 ...

Jeff Smith's Math Puzzle for September 11, 2026 - Individual interests and collective interest join hands at the local paper.

THE principal novelties in this tract are the chapters on the orthopole (with some original propositions by the author) and on orthogonal projection (mostly after Prof. Neuberg). A pretty theorem in ...

Adjust the colors to reduce glare and give your eyes a break. Use one of the services below to sign in to PBS: You've just tried to add this video to My List. But first, we need you to sign in to PBS ...