CK-12 Foundation
Ck 12: Interactive Geometry: 7.2 Sine and Cosine Ratios
Discover sine and cosine ratios in trigonometric ratios.
CK-12 Foundation
Ck 12: Definition of the Inverse of Trigonometric Ratios
[Free Registration/Login may be required to access all resource tools.] Explain the inverse of trigonometric functions.
Interactive Mathematics
Interactive Mathematics: Trigonometric Functions
Just about everything you need to know about trigonometry can be found here. Interactive examples and demonstrations help to enhance the lessons. Although not required, the tutorial uses Live Math and Scientific Notebook.
Purple Math
Purplemath: Basic Trigonometric Ratios: Examples
Demonstrates how to use trig ratios to do simple solving of triangles.
Khan Academy
Khan Academy: Reciprocal Trig Ratios
Understand the right triangle definition of sec, csc, and cot ratios.
Purple Math
Purplemath: The Unit Circle
Relates the unit circle to the method for finding trig ratios in any of the four quadrants. Demonstrates how the unit circle might be useful.
Windstream
Ojk's Pre Calculus Study Page: The Four Other Trig Functions
Trigonometry ratios and their signs are given in this explanation of the other trig functions. Graphs of tangent, cotangent, secant, and cosecant are given. Examples are included.
Khan Academy
Khan Academy: Trigonometric Ratios in Right Triangles
Learn how to find the sine, cosine, and tangent of angles in right triangles.
Khan Academy
Khan Academy: Trigonometric Ratios in Right Triangles
Given the side lengths of a right triangle, find the sine, cosine, or tangent of one of the acute angles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Homeschool Math
Homeschool Math: Introduction to Sine
This is an introductory lesson about the trigonometric function sine. Students will study several similar right triangles and the ratio of certain two sides in them.
Texas Instruments
Texas Instruments: Exploration of Trigonometry
Using TI Navigator, Cabri Jr and LearnCheck, students will explore how changing an angle in a triangle changes the ratio of the sides, and changing the sides can make changes an angle in a triangle. Students will then explore two...
Interactive Mathematics
Interactive Mathematics: Radians
Learn the definition of radians and how to calculate trig ratios using radian measures. Examples are provided showing how to convert from degrees to radians.
Other
North Carolina Su: Triangles, Circles, and Waves (Oh My!)
This site has a basic overview of trigonometry focusing on the trig functions, trig ratios, and the unit circle.
CK-12 Foundation
Ck 12: Exact Values for Inverse Sine, Cosine, and Tangent
[Free Registration/Login may be required to access all resource tools.] Find all angles on the unit circle matching exact trig ratios. Resource includes examples, videos, and practice problems.
CK-12 Foundation
Ck 12: Trigonometry: Trigonometry in Terms of Algebra
[Free Registration/Login may be required to access all resource tools.] Define trigonometric relationships with algebraic ratios.
Government of Alberta
Learn Alberta: Exploring Similarity and Congruence
Begin by watching this captivating video showing how the concepts of similarity and congruence are found in road signs. Following the video [1:27], an interactive applet allows students to resize, flip, move and rotate triangles to...
Purple Math
Purplemath: Quadrants and Angles
Explains how to model angles in the x,y-plane, and demonstrates how to extend the concept of trig ratios to angles larger than 90 degrees.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Razones Trigonometricas
In Spanish. In this interactive activity you will learn about the six trigonometric ratios, discover relationships between the trigonometric ratios of complementary and supplementary angles and the relationship between the sides of a...
Texas Instruments
Texas Instruments: Approximation of Pi Using Archimedes' Method
Students can use trigonometric ratios to discover the circumference of regular polygons inscribed within and circumscribed about a circle. These ratios will help approximate a value of pi.
Texas Instruments
Texas Instruments: Solving Problems Using Trigonometry
Solving real life problem using trig ratios. Example: Finding the angle of elevation or the angle of depression. Finding the angle between two lines. Finding equation of a line that passes through two points.
Texas Instruments
Texas Instruments: Basic Trigonometry Love or Leave It!!
This activity has the teacher to create 3 triangles on Cabri Jr. on the TI-83 or TI-84. It will prove to students how trigonometry ratios are found. It will show to the students where the ratios are derived rather than just telling the...
Interactive Mathematics
Interactive Mathematics: Sine, Cosine, Tan & Reciprocals
The definitions of the six trig ratios are presented here, along with several examples of how to determine the ratios given 2 or more sides of a right triangle.
Lawrence Hall of Science
The Math Page: Trigonometry
Concepts in Trigonometry are explained and illustrated here by a member of the math department at Borough of Manhattan Community College.
Khan Academy
Khan Academy: Solve for an Angle in Right Triangles
Given two sides in a right triangle, find one of the acute angles using trigonometry. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.