Instructional Video3:35
CK-12 Foundation

Inscribed Similar Triangles: Lesson

6th - 12th Standards
Create similar triangles with a little altitude. A section of an extensive playlist on basic geometry discusses how an altitude of a right triangle creates similar triangles. Using the theorem, the presentation finds unknown side...
Instructional Video4:37
CK-12 Foundation

Using the Pythagorean Theorem: Lesson

8th - 11th Standards
Is it right to use the converse? A segment of a basic geometry playlist introduces the Pythagorean Theorem and its converse. The video uses Pythagorean triples when finding whether a triangle is a right triangle or not.
Instructional Video4:55
CK-12 Foundation

Classifying Triangles: Lesson

4th - 8th Standards
That's correct, it is right and scalene. The video introduces the two methods for classifying triangles, sides, and angles. A resource in the playlist for basic geometry provides the definitions for each of the classifications.
Instructional Video4:04
Socratica

Introduction to the Pythagorean Theorem

7th - 10th Standards
Use a new medium to investigate an old mathematical theorem. Young mathematicians learn about the Pythagorean Theorem from a YouTube video in the Socratica Geometry playlist. They first see if a set of values is a Pythagorean triple and...
Instructional Video5:17
TED-Ed

How Many Ways Are There to Prove the Pythagorean Theorem?

8th - 12th Standards
There is more than one way to prove the Pythagorean Theorem. Euclid and Einstein found the same way to prove the Pythagorean Theorem. The video introduces several other ways to prove the theorem along with the history of its use.
Instructional Video4:02
FuseSchool

Pythagoras' Theorem

8th - 12th Standards
Explore the relationship of the square of the sides of a right triangle. After developing the Pythagorean Theorem, the video instructor presents practice problems and their solutions. She calculates the hypotenuse and then a leg of a...
Instructional Video3:05
FuseSchool

Introduction to SOHCAHTOA

9th - 12th Standards
Explore right triangle trigonometry with a thorough video lesson. The lesson instructor introduces the trigonometric ratios with an examination of right triangle sides and angles. She continues with practice writing the ratios using...
Instructional Video2:35
FuseSchool

SOHCAHTOA - Finding Missing Sides Part 2

9th - 12th Standards
Explore some right triangle trigonometry with a straightforward video lesson. The instructor presents problems requiring scholars to use trig ratios to find unknown side measures. She provides worked-out solutions for those needing...
Instructional Video
FuseSchool

Identifying the Sides of a Right Triangle

9th - 12th Standards
Find the right way to identify sides of right triangles. Scholars learn to correctly label the sides of a right triangle in the second video in a series of 16. The exercise is in preparation for determining trigonometric ratios.
Instructional Video12:55
1
1
Math Antics

The Pythagorean Theorem

4th - 8th Standards
Be sure the class gets this one right. Using a right triangle, the video introduces the Pythagorean Theorem. The presentation breaks down the theorem into its components while providing uses of the Pythagorean Theorem and its converse.
Instructional Video
FuseSchool

Introduction to SOHCAHTOA

9th - 12th Standards
You might not be able to pronounce it, but everyone remembers SOHCAHTOA. Young mathematicians learn a way to remember the three major trigonometric ratios. They see how the first letters of certain words lead to the mnemonic. 
Instructional Video2:07
MinutePhysics

E=mc² is Incomplete

9th - 12th
The most famous equation in the world isn't telling us the whole story! What if an object is actually moving? The narrator introduces momentum into the mix, resulting in the sad truth that traveling at the speed of light is almost, but...
Instructional Video10:54
Krista King Math

45-45-90 Triangles

9th - 12th Standards
45-45-90 triangles are half a square, which gives them a special status! The instructor explains the relationship of the sides of the 45-45-90 triangle using the Pythagorean Theorem as a reference. 
Instructional Video5:07
Krista King Math

Finding Perimeter Using the Pythagorean Theorem

9th - 12th Standards
What would right triangles be without the Pythagorean Theorem? Here learners see how to apply the Pythagorean Theorem to finding missing sides of triangles. The examples include both right and non-right triangles. 
Instructional Video7:59
Krista King Math

Tangent Lines of Circles

9th - 12th Standards
A video instructor explains the meaning of a line tangent to a circle. She then works through an application problem applying the tangent-radius relationship.
Instructional Video10:07
Krista King Math

30-60-90 Triangles

9th - 12th Standards
Half of an equilateral triangle is a special right triangle. A video instructor shows how to find the pattern of the side lengths for a 30-60-90 triangle. She then applies the relationship to different examples.
Instructional Video5:14
Krista King Math

Pythagorean Inequalities

9th - 12th Standards
Right, acute, or obtuse: how do you know? Learners observe how to use the Pythagorean Theorem to determine the type of triangle from a set of side lengths. The video includes an example of each triangle type.
Instructional Video3:08
Krista King Math

Pythagorean Theorem

9th - 12th Standards
A YouTube video efficiently describes the process of using the Pythagorean Theorem. It includes an example of finding the hypotenuse and another that finds the length of a leg. 
Instructional Video3:54
1
1
Curated OER

What is the Pythagorean Theorem?

6th - 11th
Need to find the length of a side of a right triangle? Just use the Pythagorean Theorem! Follow along as the tutor defines the Theorem, explains how it works, then uses it to determine the missing length of a right triangle. 
Instructional Video2:47
Curated OER

How Do You Find the Sine of an Angle in a Right Triangle?

7th - 11th
A trigonometric ratio is a ratio between two sides of a right triangle. In this problem, find sin(A) in the given right triangle. Use the ratio of the opposite side over the hypotenuse.
Instructional Video2:12
Curated OER

What are the Legs and Hypotenuse of a Right Triangle?

6th - 10th
What are all the parts of a right triangle called? What makes it a right triangle? Legs? Triangles have legs? Hypotenuse? Pythagorean Theorem? The instructor diagrams and identifies all the parts of a right triangle for you.
Instructional Video7:21
Curated OER

How Do You Find the Lateral and Surface Areas of a Cone if You Don't Know the Slant Height?

9th - 11th
Did you know you can use the Pythagorean theorem to find the slant height of a cone? You can! Just watch this tutorial and see how you can find the lateral and surface area of a given cone using slant height and the Pythagorean theorem.
Instructional Video4:19
1
1
Curated OER

How Do You Find the Area of a Trapezoid?

7th - 9th
Trapezoids can be tricky! Break down the process of finding the area of a trapezoid with an engaging math video. Learners explore area formula and shown exactly how to plug in information, solve, and simplify. 
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 -...