Khan Academy
Khan Academy: Triangles: Congruent Triangle Example 2
Students watch a video tutorial showing that segments have the same length using triangle congruence properties.
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.
Khan Academy
Khan Academy: Triangles: Congruent Triangles and Sss
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.
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.
Khan Academy
Khan Academy: Using Similar & Congruent Triangles
Sal uses the similarity of triangles and the congruence of others in this multi-step problem to find the area of a polygon.
Sophia Learning
Sophia: Using Triangles to Examine Quadrilaterals
This lesson demonstrates how to determine properties of quadrilaterals by using triangles.