Khan Academy
Khan Academy: Triangles: Similar Triangle Example Problems
Demonstration on how to determine if triangles are similar based on AA, SSS, or SAS similarity postulates.
Loyola University Chicago
Math Flix: Similar Figures: Proof Using Proportions
This QuickTime movie provides an opportunity to develop the basic geometric term, similar, by checking to see if figures are proportionaly similar. As you watch and listen to the teacher and student interact it helps clarify the thinking...
Sophia Learning
Sophia: Similar Polygons and Their Perimeters: Lesson 2
This lesson presents the relationship between similar polygons and the ratio of their perimeters. It is 2 of 5 in the series titled "Similar Polygons and their Perimeters."
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: Sas Triangle Similarity: Lesson 4
This lesson will provide examples that demonstrate how two triangles would be similar by SAS triangle similarity. It is 4 of 5 in the series titled "SAS Triangle Similarity."