Texas Instruments
Texas Instruments: Math Today When a Ruler Isn't Enough
This activity illustrates a real-life problem that uses trigonometry to solve for an unknown. students can use trigonometric ratios and inverse trigonometric relationships to determine the side of a triangle and the measure of the...
University of Saskatchewan (Canada)
Exercises in Math Readiness for University Study: Trig
Read a lesson, look at examples, and try easy, medium, and advanced problems from a variety of trigonometry topics: radian measure of angles, trigonometric functions, trigonometric identities, and modeling with trigonometric functions.
Khan Academy
Khan Academy: Solve for a Side in Right Triangles
Given one side length and an acute angle in a right triangle, find another side using trigonometry. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Purple Math
Purplemath: Inverses of Trigonometric Ratios
You know that you can take side lengths and find trig ratios, and you know you can find trig ratios (in your calculator) for angles. What is missing is a way to go from the ratios back to the original angles. And that is what "inverse...
Texas Instruments
Texas Instruments: What's the Trig?
Students will be introduced to right triangle trigonometry. They will use the TI-89 and Geometer's Sketchpad to construct a right triangle and calculate sin, cosine, and tangent of various acute angles.
Paul Dawkins
Paul's Online Notes: Solving Trig Equations
In this section we will discuss how to solve trig equations. The answers to the equations in this section will all be one of the "standard" angles that most students have memorized after a trig class. However, the process used here can...
Purple Math
Purplemath: Converting Between Radians and Degrees
Describes degrees and radians with respect to angles, the reason for the invention and use of radians, and how to convert between radians and degrees.
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...
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...
Math Planet
Math Planet: Algebra 2: Cosines
Defines and explores the law of cosines through examples and a video lesson. [1:41]
Texas Instruments
Texas Instruments: Sin, Cos, and Tan of Right Triangles
In this activity, students explore a right angled triangle and its trigonometric concepts. They investigate the trigonometric ratios for the angles of the triangle.
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...
McGraw Hill
Glencoe Mathematics: Online Study Tools: Self Check Quiz on Right Triangles
The online assessment demonstrates knowledge of concepts utilized in Geometry. The multiple choice questions test students on right triangles and trigonometry.
Analyze Math
Analyze Math: Cosine Law Problems
Here are four problems to solve using the Law of Cosines. Two are SSS problems; two are SAS problems. Two have detailed solutions; two have answers given only. Notice the link at the bottom that takes you to a Law of Cosines calculator -...
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...
Oswego City School District
Regents Exam Prep Center: Unit Circle
Two hands-on lab activities for instructors to use when teaching about the coordinate graphs of the sine, cosine, and tangent functions derived from a unit circle. The graphs of the reciprocals of the three functions are investigated....
Other
Brown Math: Remembering Trig Identities
Faced with a large number of trigonometric identities, students tend to try to memorize them all. This site the emphasis is on understanding how the functions work and on memorizing only about a half dozen of them - all the others work...
CK-12 Foundation
Ck 12: Trigonometry: Rectangular to Polar Conversions
[Free Registration/Login may be required to access all resource tools.] This lesson introduces Polar coordinates.
Purple Math
Purplemath: Greek Letters and Their Names
When you are working with geometry and trigonometry, you will see a lot of Greek letters. It will be helpful to know how the names of these letters are spelled and pronounced.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Razones Trigonometricas De Algunos Angulos
In Spanish. Observe the relationships between the trigonometric functions then test your knowledge with the activities at the end.
Cuemath
Cuemath: Cosine Function
Learn more about cosine functions by exploring unit circles, and angles, how to use them, and their various applications along with some solved examples and a few interactive questions to test your understanding.
Cuemath
Cuemath: Sine Function
A comprehensive guide for learning all about the sine function, unit circle and angles, how to use them, and their various applications. Check out the solved examples and practice questions for better understanding.
Instituto Latinoamericano de la Comunicacion Educativa
Red Escolar: Barcos en Alta Mar
In Spanish. Play submarine by using trigonometry, learn the law of sines and cosine, build an instrument to measure angles and distance and find out who was the father of Trigonometry.
Wolfram Research
Wolfram Math World: Oblique Triangle
This page gives a single-sentence definition of an oblique triangle (one with no right angles.)