FuseSchool
Triangles
In this video we are going to look at exterior angles of polygons. Exterior angles are a little strange. They make a straight line with the interior angle, rather than being the whole outside angle. There are a few different ways to...
Cerebellum
Geometry - Definitions
Understand and making sense of geometry: Triangles, and their angles. This is part 1 from the series 'Geometry Program'.
Curated Video
Nets (Part 2) (Use a net to find the surface area of a solid formed by rectangles and triangles)
The three dimensions that form a solid are: length, width, and height.
Brian McLogan
What is the Triangle Inequality Theorem - Congruent Triangles
👉 Learn about congruent triangles theorems. Two or more triangles are said to be congruent if they have the same shape and size. There are many methods to determine whether two triangles are congruent. Some of the methods include: (1)...
Amor Sciendi
Euclid: The Art of Geometry
Here we discuss the influential artist Euclid of Alexandria and his peerless work The Elements.
Curated Video
Using Equations to Find Missing Angles
In this video, the teacher explains how equations can help us find missing angles in real-world situations, using the example of floor tiles. By examining the patterns and shapes, the teacher demonstrates how to determine the measure of...
Curated Video
Comparing and Analyzing Triangles by their Sides
In this lesson, the teacher explains how to compare and analyze triangles by their sides. The lesson covers different types of triangles, including equilateral, isosceles, and scaling triangles, and how to identify them based on their...
Getty Images
A dispersive equilateral prism refracting and reflecting an incoming beam of uniform white light. Refraction of light results in the light being split into its constituent spectral colors (the colors of the rainbow)
A dispersive equilateral prism refracting and reflecting an incoming beam of uniform white light. Refraction of light results in the light being split into its constituent spectral colors (the colors of the rainbow)
Scholastic
Study Jams! Classify Triangles
Jam on with this multi-faceted activity teaching triangle classification. Start with a learner-paced lesson describing the different qualities of triangles and follow with a fun karaoke session. Also provided are two types...
CK-12 Foundation
Equilateral Triangles: Lesson
Take a second look at triangles that are equal all the way around. The video reminds viewers what an equilateral triangle is and points out that the three angles are the same. Using the fact that equilateral triangles are also isosceles,...
Math Antics
Triangles
What has three sides and is adorable? A-cute triangle. The resource introduces triangles and how to classify them by sides and angles or both. The video concludes with using the sum of the angles of a triangle to show how to solve for a...
Curated OER
What is a Triangle?
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 -...
Curated OER
How Do You Classify Triangles?
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...
Sophia Learning
Sophia: Equilateral Triangles: Lesson 2
This lesson will prepare you to distinguish an equilateral triangle based on the sides of a triangle. It is 2 of 8 in the series titled "Equilateral Triangles."
Sophia Learning
Sophia: Equilateral Triangles: Lesson 8
This lesson will prepare you to distinguish an equilateral triangle based on the sides of a triangle. It is 8 of 8 in the series titled "Equilateral Triangles."
Sophia Learning
Sophia: Equilateral Triangles: Lesson 4
This lesson will prepare you to distinguish an equilateral triangle based on the sides of a triangle. It is 4 of 8 in the series titled "Equilateral Triangles."
Virtual Nerd
Virtual Nerd: What Is a Triangle?
This tutorial explains triangles and their different types. [5:58]
Virtual Nerd
Virtual Nerd: How Do You Classify Triangles?
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]
Virtual Nerd
Virtual Nerd: How Do You Classify Triangles?
This tutorial provides practice in classifying triangles which is useful when figuring out how to solve for various sides and angles. [7:15]
Sophia Learning
Sophia: Regular Polygons Tutorial
In this video tutorial, students will determine if a polygon is regular by examining the sides and angles for congruency. Check understanding by the assessment. [2:06]
Sophia Learning
Sophia: Regular Polygons Tutorial
This video tutorial demonstrates how to use the terms equiangular and equilateral to determine if a polygon is regular or irregular. Check understanding with the assessment. [6:07]
Khan Academy
Khan Academy: Triangles: Area of an Equilateral Triangle
This video tutorial explores finding the formula for the area of an equilateral triangle with side length of s.
Khan Academy
Khan Academy: Classifying Triangles by Angles
You say you can't categorize a triangle because you don't know the length of the sides. Guess what? If you know the size of the angles you can!
Sophia Learning
Sophia: Equilateral Triangles: Lesson 5
This lesson will prepare you to distinguish an equilateral triangle based on the sides of a triangle. It is 5 of 8 in the series titled "Equilateral Triangles."