Khan Academy: Geometry: Similarity Example Where Same Side Plays Different Roles

Supplement your scholars' knowledge of angles involved with parallel lines. Using the properties of alternate interior angles and linear pairs, the presenter shows interior angles located on the same side of a transversal of parallel...

Explains how to determine unknown side lengths in a diagram that involves similar triangles where the two triangles share a side and the shared side corresponds to two different sides in each triangle.

Explains how to determine unknown side lengths of similar triangles by identifying corresponding sides and angles ans setting up proportions. The first example is a continuation from the video "Similar Triangles." Practice problems...

Explains how to identify and use similar triangles in order to determine unknown side lengths in two given diagrams. Each diagram also applies knowledge of angles formed when parallel lines are cut by a transversal. [7:37]

Explains what it means for two triangles to be similar. Diagram of similar triangles is created with two parallel lines cut by two transversals. [9:34]

Explains the minimum amount of information needed to determine if two triangles are similar. Names and illustrates the similarity postulates: AA, SSS, and SAS. [12:14]

Explains the difference between congruent triangles and similar triangles. Introduces the idea of scale factors. [9:17]

In this video tutorial [5:42], the instructor explains the ratio of the lengths of the sides in a 45-45-90 triangle using the Pythagorean theorem. Beginning of video concludes a discussion from a previous video on the ratio of the...

Interesting similarity problem where we don't have a lot of information to work with.

Demonstrates how to solve five different problems from a released California Geometry state test that involve finding the measures of angles in different polygons. This video also appears in the Geometry: Worked Examples section. [10:58]