Instructional Video5:58
Curated OER

What is a Triangle?

1st - 5th
Triangles, triangles, triangles. What makes a polygon a triangle? How many types of triangles are there? How do you determine what kind of triangle it is? Watch this video as the teacher explains 'tri' meaning three, making a triangle -...
Instructional Video7:15
Curated OER

How Do You Classify Triangles?

5th - 10th
Triangles are classified by their angle measurement as well as by the length of their sides. Here are some names that identify the types of triangles: isosceles, equilateral, scalene, obtuse, and acute. Watch this video to learn about...