Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Determine if a Triangle Is a Right Triangle

7th - 9th Standards
In this video lesson a students learns how to determine if a triangle is a right triangle by using the Pythagorean Theorem.
Instructional Video
Khan Academy

Khan Academy: Geometry: Intro to 30 60 90 Triangles

9th - 10th Standards
Solves an example problem in which the length of the hypotenuse is known and the length of a side must be determined. Explains the special relationship of the lengths of the sides of a 30-60-90 triangle using the Pythagorean theorem....
Instructional Video
Math Planet

Math Planet: Geometry: Triangles

9th - 10th Standards
Discussion of triangles through the use of examples and a video lesson. [1:08]
Instructional Video
Virtual Nerd

Virtual Nerd: What Are the Legs and Hypotenuse of a Right Triangle?

9th - 10th Standards
Features an intoduction to the names for the different parts of a right triangle. [2:13]
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
Sophia Learning

Sophia: Special Right Triangles

9th - 10th Standards
Special right triangles are investigated in this video tutorial. The lesson provides background knowledge and two videos that show the relationships of the sides in special right triangles and practice problems to test students'...
Instructional Video
Sophia Learning

Sophia: Special Right Triangles

9th - 10th Standards
Special right triangles are explored in this video tutorial. The lesson provides four videos that explain the side ratios for 45-45-90 and 30-60-90 triangles along with real-world examples involving each type of triangle.
Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Find a Missing Hypotenuse in a 45 45 90 Triangle?

9th - 10th Standards
In this tutorial, see how to solve for a missing side length by using your knowledge of 45-45-90 triangles to find a scale factor and set up an equation to solve. [4:51]
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
Imagine Learning Classroom

Learn Zillion: Find Tangent Value Using Side Ratios

9th - 10th Standards
In this lesson, you will learn how the ratios of certain sides of the triangle determine the tangent value of a particular angle by using properties of similar triangles. [2:13]
Instructional Video
Study Pug

Study Pug: Pythagorean Theorem

10th - 12th Standards
In a nutshell, Pythagorean Theorem describes the relationship between the lengths and sides of a right triangle. Watch this video for a detailed explanation along with various examples. [8:48]
Instructional Video
PatrickJMT

Patrick Jmt: Pythagorean Theorem

9th - 10th Standards
Video tutorial defines the Pythagorean theorem and features a few problems using it. [9:04]
Instructional Video
Khan Academy

Khan Academy: Ca Geometry: Similar Triangles 1

9th - 10th Standards
worked examples of similar triangles.
Instructional Video
Khan Academy

Khan Academy: Ca Geometry: More on Congruent and Similar Triangles

9th - 10th Standards
Worked examples of similar and congruent triangles.
Instructional Video
Khan Academy

Khan Academy: Triangle Similarity & the Trigonometric Ratios

9th - 10th Standards
Sal explains how the trigonometric ratios are derived from triangle similarity considerations.
Instructional Video
Khan Academy

Khan Academy: Geometry Word Problem: A Perfect Pool Shot

9th - 10th Standards
Sal uses triangle similarity to plan the perfect shot in a pool game.
Instructional Video
Khan Academy

Khan Academy: Area of a Regular Hexagon

9th - 10th Standards
Using what we know about triangles to find the area of a regular hexagon.
Instructional Video
Khan Academy

Khan Academy: Special Right Triangles Proof (Part 2)

9th - 10th Standards
Showing the ratios of the sides of a 45-45-90 triangle are 1:1:sqrt(2)
Instructional Video
Khan Academy

Khan Academy: Special Right Triangles Intro (Part 2)

9th - 10th Standards
A few more 45-45-90 triangle examples and an introduction to 30-60-90 triangles.
Instructional Video
Khan Academy

Khan Academy: Special Right Triangles Proof (Part 1)

9th - 10th Standards
Learn how to prove the ratios between the sides of a 30-60-90 triangle.
Instructional Video
Khan Academy

Khan Academy: Special Right Triangles Intro (Part 1)

9th - 10th Standards
Introduction to 45-45-90 triangles.
Instructional Video
Sophia Learning

Sophia: Using Right Triangle Trigonometry to Find the Area of Regular Polygons

9th - 10th Standards
This lesson will demonstrate how to use right triangle trigonometry and special right triangles (45-45-90 and 30-60-90) to find the area of triangles given the side lengths of the polygon. It is 3 of 4 in the series titled "Using Right...
Instructional Video
Sophia Learning

Sophia: Using Right Triangle Trigonometry to Find the Area of Regular Polygons

9th - 10th Standards
This lesson will demonstrate how to use right triangle trigonometry and special right triangles (45-45-90 and 30-60-90) to find the area of triangles given the side lengths of the polygon.