Texas Instruments
Texas Instruments: The Tangent Ratio
In this activity students explore the tangent ratio. Students construct a right triangle using perpendicular lines, and a line that forms the hypotenuse of the triangle. When students construct the hypotenuse line it is very important...
ClassFlow
Class Flow: Ratio and Proportion Geometry Review
[Free Registration/Login Required] This flipchart is a Jeopardy style review for Ratio and Proportion. Comes form the McDougal Littell Geometry book.
Illustrative Mathematics
Illustrative Mathematics: A sse.b.4: Triangle Series
The purpose of this task is to emphasize the adjective "geometric" in the "geometric" series, namely, that the algebraic notion of a common ratio between terms corresponds to the geometric notion of a repeated similarity transformation....
Homeschool Math
Homeschool Math: Introduction to Sine
This is an introductory lesson plan about the trigonometric function sine. Young scholars will study several similar right triangles and the ratio of certain two sides in them.
Purple Math
Purplemath: Proportions: Introduction
Explains the basics and terminology of proportions.