Video exploring triangles and illustrating fractal concepts such as the Koch snowflake

Review intuition behind the triangle inequality theorem in this short video.

This video demonstrates how to use the triangle sum theorem, properties of isosceles triangles, and special angle pairs formed when parallel lines are cut by a transversal to set up an equation using given algebraic expressions for angle...

Demonstration on how to determine if triangles are similar based on AA, SSS, or SAS similarity postulates.

This video tutorial explains how to use triangle congruence to identify measures of corresponding sides and angles in triangles. Defines side-side-side (SSS) postulate.

Shows how to find the measure of missing angles using the triangle sum theorem and vertical angles.

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.

More Pythagorean Theorem examples. Introduction to 45-45-90 triangles.

A video proving that the given triangles are congruent by ASA.

Video tutorial uses examples to introduce triangle inequality. [6:15]

Video tutorial uses examples to reinforce understanding of how to find the measure of each angle of a polygon. [9:26]

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]

Video tutorial defines the Pythagorean theorem and features a few problems using it. [9:04]

Learn to categorize triangles as scalene, isosceles, equilateral, acute, right, or obtuse.

Work through sample problems categorizing triangles as scalene, isosceles, equilateral, acute, right, or obtuse.

Sal first solves a problem where he orders the sides of a triangle given the angles, then solves a problem where he orders the angles of a triangle given the sides.

Worked examples of triangles and parallelograms.

This collection includes 16 Peg + Cat video clips about geometry including 2-D and 3-D shapes.

This lesson [2:00] will define the phrase corresponding parts (e.g. angles, sides, etc.). It is 1 of 5 in the series titled "Corresponding Parts."

This lesson will go over the steps involved in finding the missing angle of a given triangle.

Following this lesson, the angle measure of one non-right angle of a right triangle, and the right angle symbol in the right angle of the triangle, you'll be able to determine the value of the missing angle. It is 2 of 9 in the series...

Following this lesson, the angle measure of one non-right angle of a right triangle, and the right angle symbol in the right angle of the triangle, you'll be able to determine the value of the missing angle. It is 6 of 9 in the series...

In this lesson, you'll learn how to use the lengths of two sides of a triangle and the ratio of the side lengths to find the length of the missing side. It is 2 of 9 in the series titled "Finding the Missing Side of a 45-45-90 Triangle."

In this lesson, you'll learn how to use the lengths of two sides of a triangle and the ratio of the side lengths to find the length of the missing side. It is 3 of 9 in the series titled "Finding the Missing Side of a 45-45-90 Triangle."