An icon in the shape of a lightning bolt. Impact Link 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 ...

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 ...

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 ...

Many children's concept of a triangle is limited to the familiar equilateral triangle with a horizontal base. In this lesson, students will explore and identify a variety of triangular shapes using ...

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 ...