Worksheet
Curated OER

Trig Cut Ups

For Students 9th - 11th
In this trigonometry worksheet, students rearrange 16 squares to a form one large square in which all of the trig identities match up. There is an answer key.
Worksheet
Curated OER

Evaluating Trig equations and Solving Trig Identities

For Students 9th - Higher Ed
In this trigonometry worksheet, students match trig expressions to their exact value, evaluate trig equations, graph trig equations, and prove trig identities. There are 61 questions.
Worksheet
Curated OER

Trigonometric Identities

For Students 11th - Higher Ed
In this trigonometry worksheet, students derive the 6 different trigonometric identities. They use the identities to solve problems by multiplication of trig ratios. There are 102 trig questions to be solved.
Interactive
Curated OER

Connect The Dots Trig. Identities

For Students 10th - 11th
In this trig. identities learning exercise, students connect the dots to equivalent values.  Then students find the isosceles right triangle formed.  Solutions are provided.
Activity
Windstream

Ojk World of Math: Relationships Between the Functions

For Students 9th - 10th Standards
This tutorial discusses relationships among all the trig identities. Examples are given on how to apply them to simplify trig expressions and prove identities.
Unknown Type
Mathematics Archives

Math Archives: Visual Calculus: 47 Trig Identities!

For Students 9th - 10th Standards
This makes for a great handout for students and teachers, alike! A comprehensive list of 47 commonly-used trig identities.
Activity
Other

North Carolina Su: Triangles, Circles, and Waves (Oh My!)

For Students 9th - 10th Standards
This site has a basic overview of trigonometry focusing on the trig functions, trig ratios, and the unit circle.
Activity
Math Medics

S.o.s. Math: Double Angle and Half Angle Formulas

For Students 9th - 10th
Double angles and half angles are explained through step by step examples. The steps are clear and easy to follow.
Activity
Clark University

Clark University: Dave's Short Trig Course: Summary of Trig Identities

For Students 9th - 10th Standards
This Clark University page is an excellent reference page for trig identities. It is a little difficult to read so take your time with the formulas. If you remember soh - cah - toa, the other formulas are right here.
Handout
Cool Math

Coolmath: Pre Calculus Other Identities to Know

For Students 10th - 12th Standards
One page reference sheet of a quick recall of the Trig Identities.
Activity
Math2

Math2.org: Trigonometry Functions

For Students 9th - 10th Standards
A complete look at trig functions. From an "overview," page giving general definitions and important vocab words, to a listing of the 12 trig functions, to an explanation of the three modes used in trigonometry, to the procedures of how...
Handout
Math Words

Math Words: Cofunction Identities

For Students 9th - 10th Standards
This MathWords.com site, which is a glossary of math terms, shows the relationship in radians and degrees between sin and cos, tan and cot, and sec and csc.
Activity
Math2

Math2.org: Trigonometric Identities

For Students 9th - 10th Standards
This personal site is a listing of numerous trig identities. A great reference site.
Activity
Interactive Mathematics

Interactive Mathematics: Trigonometric Functions

For Students 9th - 10th
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.