The Math Forum: Ask Dr. Math: Determining Triangle Similarity

What do you need to prove triangles are similar? Learners answer this question through a construction exploration. Once they establish the criteria, they use the congruence and proportionality properties of similar objects to find...

Although a rather complicated topic, this video clearly explains the concept of solving problems involving similar triangles. It employs problem-solving to determine whether two figures are similar triangles. In addition, it provides...

Two sets of congruent angles leads to three. Using diagrams of two triangles, the presentation intuitively shows that if two sets of angles are congruent, the third set is too. The portion of a geometry playlist uses that information to...

Zoom in to reveal more of the same. The resource introduces the concept of self similarity. Using a simple example, the video—part of a larger playlist covering geometry concepts—illustrates the meaning of a self similarity figure.

This site provides links to questions sent in to Dr. Math about proofs. Topics covered include what proofs are, how to understand them, and how to build them, and much more. Be sure to click on the links which you believe may be helpful.

A student asks Dr. Math for help to understand the concept of direct and inverse variation. The Dr. begins with the very basics and gives a great discussion on variation. The Dr. includes the thinking process and examples.

A student asks Dr. Math how to evaluate a composite function. Dr. Math gives a systematic way to evaluate composite functions. Be sure to read the second response as well to findout how to evaluate functions of several compositions and...

Dr. Math gives an inspiring and clear discussion about equations of lines and lines as functions. The Dr. discusses the benefits of the standard form of a line and prompts the student with an equation which can not be written in the...

This site is an archive of questions posed by students and the general public about geometry which are responded to by "Dr. Math."

This modern animation and discussion of the ancient secrets of Pascal's triangle manages to be topical, engaging, and mathematically deep all at the same time. A great introduction to the power of number theory across multiple math...