Khan Academy: Geometry: Similar Example Problems

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 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. [6:05]

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]

Explains how to identify and use similar triangles in order to determine unknown side lengths in two given diagrams.

Demonstrates how to solve a problem from the 2000 American Invitational Mathematics Examination which involves finding the perimeter of a rectangle covered by nine overlapping squares. [9:56]

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]

In this video tutorial, the instructor demostrates how to apply the special relationship between the legs and hypotenuse of a 30-60-90 triangle. Solves two different example problems using the relationship. Practice problems available....

Solves an example problem in which the length of the hypotenuse is known and the length of a side must be determined. Explains the special relationship of the lengths of the sides of a 30-60-90 triangle using the Pythagorean theorem....