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...
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: 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...
Oswego City School District
Regents Exam Prep Center: Area of a Triangle and Parallelogram Using Trig
How can trigonometry be used to find the area of a triangle or parallelogram? Does the triangle need to be a right triangle, and how accurate can the results possibly be? The answers to these questions are found here along with several...
CK-12 Foundation
Ck 12: Geometry: Sine, Cosine, Tangent
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to find the sine, cosine, and tangent of right triangles.
CK-12 Foundation
Ck 12: Geometry: Sine, Cosine, Tangent
[Free Registration/Login may be required to access all resource tools.] Find the sine, cosine, and tangent of right triangles.
Wolfram Research
Wolfram Math World: Oblique Triangle
This page gives a single-sentence definition of an oblique triangle (one with no right angles.)
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.
CK-12 Foundation
Ck 12: Determination of Unknown Triangle Measures Given Area
[Free Registration/Login may be required to access all resource tools.] Looks at triangle problems where you are given the area and must use trigonometry to find unknown sides or angles.
CK-12 Foundation
Ck 12: Geometry: Inverse Trigonometric Ratios
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to use inverse trigonometric ratios to solve for missing angles in right triangles.
Curated OER
Zona Land: Trigonometry Right Triangles
Introduction to right triangles and how to solve them using trigonometric functions. Very nice interactive demonstration of what happens when the angle measurements change and how it effects the calculations. This visual might be just...
Curated OER
Zona Land: Trigonometry Right Triangles
Introduction to right triangles and how to solve them using trigonometric functions. Very nice interactive demonstration of what happens when the angle measurements change and how it effects the calculations. This visual might be just...
Curated OER
Zona Land: Trigonometry Right Triangles
Introduction to right triangles and how to solve them using trigonometric functions. Very nice interactive demonstration of what happens when the angle measurements change and how it effects the calculations. This visual might be just...
Curated OER
Zona Land: Trigonometry Right Triangles
Introduction to right triangles and how to solve them using trigonometric functions. Very nice interactive demonstration of what happens when the angle measurements change and how it effects the calculations. This visual might be just...
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...
Purple Math
Purplemath: The Pythagorean Theorem
Defines the Pythagorean Theorem, and demonstrates how to use this Theorem in connection with right-angled triangles.
Sophia Learning
Sophia: Trigonometric Values From a Calculator: Lesson 2
This lesson will illustrate how to use a calculator to find the value of a trigonometric value. It is 2 of 5 in the series titled "Trigonometric Values from a Calculator."
Sophia Learning
Sophia: Trigonometric Values From a Calculator: Lesson 5
This lesson will illustrate how to use a calculator to find the value of a trigonometric value. It is 5 of 5 in the series titled "Trigonometric Values from a Calculator."
CK-12 Foundation
Ck 12: Geometry: Laws of Sines and Cosines
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to find missing sides and angles in non-right triangles using the Laws of Sines and Cosines.
Khan Academy
Khan Academy: Angular Measure 2
Looking for an easier way to do angular measurements? This page introduces you to a trick by using skinny triangles with small angles. The skinny triangles lets the astronomer assume right triangles and then they can use trigonometry to...