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 Is the Triangle Sum Theorem?

9th - 10th Standards
Watch this tutorial to learn about the Triangle Sum theorem which is useful in finding interior angle measurements. [4:48]
Instructional Video
Sophia Learning

Sophia: Pythagorean Theorem

8th - 9th Standards
Presents two short videos (under two minutes) explaining the Pythagorean Theorem. Includes short quiz.
Instructional Video
Sophia Learning

Sophia: Congruent Triangles: Lesson 3

9th - 10th Standards
This lesson will define the term congruent as it relates to triangles. It is 3 of 11 in the series titled "Congruent Triangles."
Instructional Video
Khan Academy

Khan Academy: Worked Examples: Geometry: Geometry: Triangles and Parallelograms

4th - 8th Standards
Students explore the properties of triangles and parallelograms in this video tutorial.
Instructional Video
Khan Academy

Khan Academy: Triangles: Intro to 30 60 90 Triangles

9th - 10th Standards
Explains the special relationship of the lengths of the sides of a 30-60-90 triangle using the Pythagorean theorem.
Instructional Video
Khan Academy

Khan Academy: Worked Examples: Geometry: Pythagorean Theorem, Area

9th - 10th Standards
Students watch a video tutorial to learn how to solve area problems of composite figures using the Pythagorean Theorem.
Instructional Video
Khan Academy

Khan Academy: Triangles: Another Pythagorean Theorem Proof

9th - 10th Standards
Students explore the Pythagorean Theorem by exploring a visual proof of the Theorem as they watch a video tutorial.
Instructional Video
Sophia Learning

Sophia: Calculating the Area of a Triangle

6th - 8th Standards
Use different size triangle to determine how to solve for the area in this video lesson. Take quiz to check understanding. [3:41]
Instructional Video
Sophia Learning

Sophia: Calculating the Area of a Triangle

9th - 10th Standards
This video lesson demonstrates how to calculate the area of a triangle. It includes detailed examples including ones that use the Pythagorean Theorem. Students can check their understanding with an assessment. [10:43]
Instructional Video
Sophia Learning

Sophia: Converse of the Pythagorean Theorem

9th - 10th Standards
Use the Pythagorean theorem to determine if the triangle is a right triangle. Assess learning with a quiz.
Instructional Video
Sophia Learning

Sophia: Properties of Equilateral Triangle and Takin' It 2 the Streets

9th - 10th Standards
Use examples to solve for the angles of equilateral triangles in a PowerPoint presentation. Includes video. [4:18]
Instructional Video
Sophia Learning

Sophia: Pythagorean Theorem and Right Triangles

9th - 10th Standards
Determine if the Pythagorean theorem can be used with triangles that are not right triangles. Assess learning with a quiz.
Instructional Video
Sophia Learning

Sophia: The Pythagorean Theorem

9th - 10th Standards
Determine how to find the missing side length or the hypotenuse of a right triangle using the Pythagorean theorem. Check understanding with a quiz.
Instructional Video
Sophia Learning

Sophia: Area of a Triangle

9th - 10th Standards
This video tutorial shares several examples of different types of triangles as they are used to determine the area of each triangle. Assessment checks understanding. [6:54]
Instructional Video
Sophia Learning

Sophia: Calculating the Perimeter of a Triangle

9th - 10th Standards
Solve for the perimeter of different triangles and take a quiz. [3:41]
Instructional Video
Sophia Learning

Sophia: Pythagorean Theorem Proof

9th - 10th Standards
Find the area of several figures to prove the Pythagorean theorem. Complete quiz to check understanding. [5:16]
Instructional Video
Virtual Nerd

Virtual Nerd: Find Missing Angles in an Isosceles Triangle Using Right Triangles

9th - 10th Standards
Discover how identifying your triangle first can be very helpful in solving for a missing interior angle measurement. [3:40]
Instructional Video
Virtual Nerd

Virtual Nerd: Determine if a Triangle Is a Right Triangle if You Know Its Sides

9th - 10th Standards
Take a look at this tutorial and learn how to use the Pythagorean theorem to see if a triangle is a right triangle. [2:49]
Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Find the Length of a Leg of a Right Triangle?

9th - 10th Standards
The Pythagorean theorem is useful in solving how to find the missing length of a side of a right triangle. Check out this tutorial to see how it's done. [4:09]
Instructional Video
Math Antics

Math Antics: The Pythagorean Theorem

5th - 9th Standards
Gain a basic understanding of the Pythagorean Theorem by watching this easy to understand video tutorial. Additional resources are available as part of a paid subscription service. [12:55]
Instructional Video
Khan Academy

Khan Academy: Triangles: Pythagorean Theorem Proof Using Similarity

9th - 10th Standards
This video shows a proof for the Pythagorean Theorem by breaking a right triangle into two similar triangles and setting up ratios of corresponding sides.
Instructional Video
Khan Academy

Khan Academy: Triangles: Pythagorean Theorem Ii

9th - 10th Standards
More Pythagorean Theorem examples. Introduction to 45-45-90 triangles.
Instructional Video
Khan Academy

Khan Academy: Ca Geometry: Pythagorean Theorem, Area

6th - 8th Standards
36-40, Pythagorean Theorem and area.