Instructional Video2:31
Curated Video

Types of Triangles

3rd - Higher Ed
This video will explain the four types of triangles and their properties: right-angled, equilateral, isosceles and scalene triangles. Practice questions are at the end of the video.
Instructional Video1:05
Brian McLogan

What is an acute triangle

12th - Higher Ed
👉 Learn the essential definitions of triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of their angles or on the basis of their side lengths. The classification of triangles on the bases of their...
Instructional Video7:14
Let's Tute

Heron's Formula for Calculating Areas of Triangles and Quadrilaterals

9th - Higher Ed
This video explains how to calculate the area of triangles using Heron's formula, which only requires the length of the sides. It also shows how Heron's formula can be used to calculate the area of any type of quadrilateral if all the...
Instructional Video1:55
NUMBEROCK

Triangles

K - 5th
Skateboards, mountain climbing, billiards' Don't you just love this stuff? That's why NUMBEROCK put it all into this song about triangles that is filled with real-world connections. Triangles are all around us, so it is easy to make this...
Instructional Video8:36
Let's Tute

Types of Triangles Based on angles and sides - Geometry

9th - Higher Ed
In this online video we will learn Types of Triangles based on angles and sides.
Instructional Video
Massachusetts Institute of Technology

Mit: Blossoms: Are Random Triangles Acute or Obtuse?

9th - 10th
An MIT mathematics professor examines the probability of a random triangle being either obtuse or acute in a video [32:44] on geometrical probability. Video is accompanied by a teacher's guide, transcript, and several links on linear...
Instructional Video
Massachusetts Institute of Technology

Mit: Blossoms: The Broken Stick Experiment

9th - 10th
An MIT engineering professor leads teachers and students through an activity in triangle formation and probability that requires a meter stick and other basic classroom materials. This video [33:08] is accompanied by a teacher's guide,...
Instructional Video
Sophia Learning

Sophia: Equilateral Triangle Interior Angles Practice Problems: Lesson 1

9th - 10th Standards
This lesson will provide practice problems that involve solving for unknown angle and side measures of equilateral triangles. It is 1 of 5 in the series titled "Equilateral Triangle Interior Angles Practice Problems."
Instructional Video
Sophia Learning

Sophia: Scalene Triangles: Lesson 4

9th - 10th
After this lesson, you'll be able to pinpoint a scalene triangle based on the fact that no sides or angles in a scalene triangle are congruent. It is 4 of 6 in the series titled "Scalene Triangles."
Instructional Video
Sophia Learning

Sophia: Triangle Angle Combinations: Lesson 5

7th - 8th
This lesson explains how you can have 3 acute angles, 1 obtuse and 2 acute angles or 1 right and 2 acute angles in a triangle. It is 5 of 7 in the series titled "Triangle Angle Combinations."
Instructional Video
Khan Academy

Khan Academy: Classifying Triangles

4th Standards
Discusses the different types of triangles and their angles. [6:00]
Instructional Video
Khan Academy

Khan Academy: Classifying Triangles by Angles

4th Standards
Explains how to classify a triangle just by knowing the angle sizes. [5:30]
Instructional Video
Virtual Nerd

Virtual Nerd: What Is a Triangle?

9th - 10th Standards
This tutorial explains triangles and their different types. [5:58]
Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Classify Triangles?

9th - 10th Standards
If you know what kind of triangle you're looking at, it's much easier to figure out how to solve for various sides and angles. Use this tutorial to practice classifying triangles. [7:15]
Instructional Video
Virtual Nerd

Virtual Nerd: What Are Acute, Obtuse, and Right Triangles?

9th - 10th Standards
Take a look at this tutorial and learn about some of the different kinds of triangles. [4:25]
Instructional Video
Virtual Nerd

Virtual Nerd: What Are Equilateral, Isosceles, and Scalene Triangles?

9th - 10th Standards
Watch this tutorial to learn about some of the different kinds of triangles. [5:33]
Instructional Video
CK-12 Foundation

Ck 12: Elem Math: Classifying Triangles Based on Equal Sides

3rd - 5th Standards
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview on how to classify triangles based on side length.
Instructional Video
CK-12 Foundation

Ck 12: Elem Math: Overview of Triangle Classifications

3rd - 5th Standards
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview on how to classify triangles.
Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Classify Triangles?

3rd - 5th Standards
This tutorial provides practice in classifying triangles which is useful when figuring out how to solve for various sides and angles. [7:15]
Instructional Video
Khan Academy

Khan Academy: Triangles: 45 45 90 Triangle Side Ratios

9th - 10th
Showing the ratios of the sides of a 45-45-90 triangle in this short video.
Instructional Video
Sophia Learning

Sophia: Categorizing Triangles With Congruency

9th - 10th
In this video tutorial, triangles are classified as isosceles, equilateral, and scalene by the congruency of their sides. Assess learning with a quiz. [1:52]
Instructional Video
Sophia Learning

Sophia: Classifying Triangles

9th - 10th Standards
This video lesson describes and provides examples of right, acute, and obtuse triangles. Students can check their understanding with an assessment. [2:24]
Instructional Video
Sophia Learning

Sophia: Classifying Triangles

6th - 8th
In this video tutorial, students learn how to classify triangles based on the angles. Topics include right, obtuse, and acute triangles. A short assessment is included to follow the lesson. [4:40]
Instructional Video
Sophia Learning

Sophia: Classifying Triangles by Angle

9th - 10th Standards
This video lesson shows examples of classifying triangles by their angle measurements. Students can check their understanding with an assessment. [3:54]