Khan Academy
Khan Academy: Ca Geometry: More on Congruent and Similar Triangles
Worked examples of similar and congruent triangles.
Khan Academy
Khan Academy: Triangle Similarity & the Trigonometric Ratios
Sal explains how the trigonometric ratios are derived from triangle similarity considerations.
Khan Academy
Khan Academy: Geometry Word Problem: A Perfect Pool Shot
Sal uses triangle similarity to plan the perfect shot in a pool game.
Sophia Learning
Sophia: Similar Triangles: Lesson 3
In this lesson, you'll learn the definition, proportion, and notation of similar triangles. It is 3 of 5 in the series titled "Similar Triangles."
Sophia Learning
Sophia: Similar Triangles: Lesson 4
In this lesson, you'll learn the definition, proportion, and notation of similar triangles. It is 4 of 5 in the series titled "Similar Triangles."
Sophia Learning
Sophia: Similar Triangles: Lesson 1
In this lesson, you'll learn the definition, proportion, and notation of similar triangles. It is 1 of 5 in the series titled "Similar Triangles."
Sophia Learning
Sophia: Using Similar Triangles to Make Indirect Measurements
This lesson explains why similar triangles can be used to make indirect measurements, and provides an example.
Sophia Learning
Sophia: Using Triangles to Examine Quadrilaterals
This lesson demonstrates how to determine properties of quadrilaterals by using triangles.