Socratica
Pythagorean Theorem Proof
No geometry class is complete without a proof. A short video in the Socratica Geometry playlist covers an algebraic proof of the Pythagorean Theorem. Simplifying an equation with two equivalent expressions for the area of a square leads...
Socratica
Introduction to the Pythagorean Theorem
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...
TED-Ed
How Many Ways Are There to Prove the Pythagorean Theorem?
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.
FuseSchool
Pythagoras' Theorem
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...
Math Antics
The Pythagorean Theorem
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.
National Science Foundation
Science of NFL Football: Pythagorean Theorem
Physics can make football players better. A creative video shows learners how to apply the Pythagorean Theorem to defensive situations. The first of a 10-part video series calculates the distance a defender needs to cover using right...
Krista King Math
Surface Area of Cones
Formulas are an essential part of mathematics, so help your class master them. The concept video exposes learners to the elements of the surface area formula for cones. The examples demonstrate the process of using measurements within...
Krista King Math
45-45-90 Triangles
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. 
Krista King Math
Finding Perimeter Using the Pythagorean Theorem
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. 
Krista King Math
Tangent Lines of Circles
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.
Krista King Math
30-60-90 Triangles
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.
Krista King Math
Pythagorean Inequalities
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.
Krista King Math
Pythagorean Theorem
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. 
Brightstorm
Introduction to Polar Coordinates - Concept
Learning polar coordinates does not require visiting the North Pole, though explaining igloos is much easier using polar coordinates. The lesson begins with a video explaining how to find coordinates on a spherical plane and how to...
Brightstorm
Pythagorean Theorem Proofs
Your class knows the Pythagorean Theorem, but can they prove it? A series of three videos shows two proofs of the Pythagorean Theorem and use it to classify triangles. 
National Education Association
Use Coordinate Geometry to Represent and/or Solve Problems
A geometry video explains how to solve for midpoint, length of a line, and use the Pythagorean Theorem. It includes multiple guided practice problems for all three equations.
Curated OER
What is the Pythagorean Theorem?
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. 
Curated OER
SAT Prep: Test 1 Section 2 Part 1
Beginning a series based on The Official SAT Study Guide(first edition), the speaker (Sal) deftly demonstrates how to work through the types of problems typically seen on the SAT. He assumes that the reader is also working from the...
Curated OER
What are the Legs and Hypotenuse of a Right Triangle?
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.
Curated OER
How Do You Find the Lateral and Surface Areas of a Cone if You Don't Know the Slant Height?
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.
Curated OER
How Do You Determine if a Triangle Is a Right Triangle if You Know its Sides?
Use the Pythagorean Theorem formula to check if this given triangle, with the given lengths of each side, is a right triangle. It's as simple as plugging the given values into the formula and doing the math to see if the solution checks...
Curated OER
What Is the Distance Formula?
Find the distance between two points on a coordinate plane. How is that done? Let's take a look at the distance formula. What's the distance formula? Well, it's a form of the Pythagorean Theorem. How? Watch the instructor diagram and...
Curated OER
Understanding the Pythagorean Theorem
Who is Pythagoras and what is the Pythagorean Theorem? Ben knows and he's made a video all about it! The Pythagorean Theorem is defined, the procedure is demonstrated, and an example is provided. Ben also mentions how the theorem is used...
Curated OER
Area of a Rectangle - Geometry Help
How on earth is one to find the area of a rectangle when he doesn't know the width? Using the diagonal of the rectangle, the length, and the Pythagorean Theorem the missing side is determined and the area is discovered. This clip is...