CK-12 Foundation
Ck 12: Geometry: Aa Similarity
[Free Registration/Login may be required to access all resource tools.] Use the AA Similarity Postulate to determine if triangles are similar.
CK-12 Foundation
Ck 12: Geometry: Aa Similarity (Intermediate)
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to identify whether or not two triangles are similar using AA Similarity.
PBS
Pbs: Scale City: Inverse Proportions and Shadows in the Real World
In this video, students take a quick trip through the history of drive-in theaters and are then asked to consider the question, "What is the relationship between the size of an object's shadow and the object's distance from a light...
Purple Math
Purplemath: Ratios
Explains the basic terminology and formatting of ratios, and demonstrates how to solve typical exercises.
Other
Curriculum Link: Proportional Tax Definition
This site from Curriculum Link provides a somewhat brief definition of proportional tax and provides a graph as well. A good place to get a little background information on the tax.
Other
All Elementary Mathematics: Proportionality and Ratio
A brief explanation of the mathematical relationship between ratio, proportion, and proportionality. Examples are included.
Purple Math
Purplemath: Proportions: Introduction
Explains the basics and terminology of proportions.