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 ...

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 ...

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' ...