Purple Math
Purplemath: Special Angle Values: 30 60 90 and 45 45 90 Triangles
Explains a simple pictorial way to remember basic reference angle values. Provides other memory aids for the values of trigonometric ratios for these "special" angle values, based on 30-60-90 triangles and 45-45-90 triangles.
Exploratorium
Exploratorium: Ilion High: Build a Clinometer
Instructions for building a clinometer are given on this page. Clinometers can be used to measure the angle of elevation of a right triangle, and in turn find the height of large objects.
Mathigon
Mathigon: Geometry: Circle and Pi: Degrees and Radians
Rather than dividing a circle into some number of segments (like 360 degrees), mathematicians often prefer to measure angles using the circumference of a unit circle - a circle with radius 1. This way of measuring angles is called...
CK-12 Foundation
Ck 12: Trigonometry: Inverses by Mapping
[Free Registration/Login may be required to access all resource tools.] Find the inverse of a trig function by mapping.
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.
Other
University of Cambridge: Starry Messenger: Hipparchus and the Astrolabe
A summary of Hipparchus' achievements as an astronomical observer, concentrating on the possibility that he invented the astrolabe, a device used to tell the time at night from stellar positions. Contains more links on Hipparchus.
Alabama Learning Exchange
Alex: Slide Into the Past
Learners will be introduced to the slide rule through A brief history on its use. They will practice simple calculations (multiplying and finding values of trigonometric, exponential, and logarithmic functions) using a virtual slide rule.
Alabama Learning Exchange
Alex: Conic Sections: Playing With Parabolas
Through a mixture of online exploration, and teacher instruction, students will discover how parabolas are formed and will be able to use the key components from a graph (vertex, focus and directrix,) to generate the equation of a graph.
Alabama Learning Exchange
Alex: Rags to Riches or Riches to Rags?
For this lesson young scholars will apply the interest formulas to make the best investment decision for our fictional character Algebrea Calculique. The students will be provided with a story explaining the situation that Algebrea faces...
Alabama Learning Exchange
Alex: How High Did My Rocket Go?
This is a lab in which the students will calculate the height of an air or water rocket by using trigonometry.
Alabama Learning Exchange
Alex: Traveling Around the Unit Circle
This lesson is intended to review the key ideas associated with trigonometric functions.The design of this lesson provides a collection of reproducible activities to be used in a classroom setting where learners have varied backgrounds /...
Alabama Learning Exchange
Alex: "Woody Sine"
The students will discover the shape of the sine function without creating a t-chart. The students will create a sine function using toothpicks. The students will then discover how the amplitude (height) and the period (number of compete...
CK-12 Foundation
Ck 12: Algebra Ii: 4.2 Right Triangle Trig Extended to Circles With a Model
This section explores the relationship between right triangles, circles, and trigonometry. It investigates how a right triangle that is set inside a circle and rotates around the circle is connected to trigonometric functions and their...
Khan Academy
Khan: Lesson 16: Part 2 Coordinate Geometry; Trigo and Radians; Complex Numbers
2 OF 2 FOR ADDITIONAL TOPICS IN MATH. Students will use the coordinate plane and equations of lines and circles to describe figures; create the equation of a circle given the figure or use the structure of a given equation to determine a...
Cuemath
Cuemath: Trigonometry
A comprehensive guide for learning all about the basics of trigonometry, the various identities-formulas of trigonometry, solved examples, and practice questions.
Purple Math
Purplemath: Using Identities to Evaluate
Demonstrates how to evaluate trigonometric functions by using trig identities.
Mathematics Archives
Math Archives: Trigonometric Substitution
This resource has many examples of integration using trigonometric substitution that the student can work on and then check their answers. Includes hints.
Curated OER
Zona Land: Overlapped Graph of the Six Trig Functions
An overview of the six trig functions and their graphs. The site is a little difficult to navigate but is good for finding a graph of a trig function.
Math2
Math2: Trigonometric Graphs
Sketches of the graphs of the 12 "parent," trigonometry functions are given: sine, cosine, tangent, secant, cosecant, cotangent, arcsine, arccosine, arctangent, arcsecant, arccosecant, and arccotangent.
Math2
Math2.org: Trigonometry Functions
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...
Math2
Math2.org: Table of Integrals
Seven tables are provided which give the rules for integrating powers of x, exponential and logarithmic integrals, trigonometric integrals, and hyperbolic integrals. Very detailed step-by-step proofs are given for some of the more...
Math2
Math2.org: Trigonometry Tables
Three trig tables are provided for student and teacher reference. The first table lists the sine, cosine, tangent, secant, cosecant, and cotangent values of all whole-number angles from 0 to 90. The radian equivalent (to four decimals)...
Wolfram Research
Wolfram Math World: Trigonometric Functions
This site provides a listing of the trigonometric functions and their inverses. Their notation is also addressed along with links to each of the fundamental trigonometric functions.
University of Georgia
University of Georgia: Navigation Problems
These two navigation problems employ the use of the law of sines or cosines and basic trigonometry. Each problems includes links to a sketch of the problem for visual help, and to a solution.