# Geometry - 4th Edition

## Chapter 6: Similar Triangles

Some links are repeated for use with more than one lesson.

### This site applies to the entire chapter.

http://www.freemathhelp.com/Lessons/Geometry_Similar_Triangles_BB.htm
This site contains a video tutorial with notes on similar triangles.

### 6.1 Ratio and Proportion

http://www.mathleague.com/index.php?option=com_content&view=article&id=80&Itemid=67
NEW This site defines ratio, proportion, and rate, and has examples of each.

http://www.math.com/school/subject1/lessons/S1U2L2GL.html

### 6.2 Similarity

http://www.cut-the-knot.org/ctk/Similarity.shtml
This site has an article called “A Case of Similarity” that proves the similarity of triangle theorems.

### 6.3 Proportions in Similar Triangles

http://www.regentsprep.org/regents/math/geometry/GP11/indexGP11.htm
NEW This page contains links to several pages that explain and provide practice for using proportions to prove triangles are similar.

### 6.4 Indirect Measurement

http://mathforum.org/sanders/connectinggeometry/ch_09Similar.html
NEW This page includes an explanation of how you can use indirect measurements with similar triangles to measure distant objects.

### 6.5 Proportions in Right Triangles

https://www.opened.io/?res_id=72581#!/resources/364561
NEW This short video lecture demonstrates using similar right triangles to measure the height of objects.

http://www.regentsprep.org/Regents/math/geometry/GP12/indexGP12.htm
NEW This page includes an explanation and practice for using proportions in right triangles to solve problems.