In the July 2013 issue of United Airlines' Hemisphere Magazine, a pilot responded to a question about how far in the distance he could see at different altitudes. The solution involved right triangles, lines of tangency to a circle, and...

[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.

[Free Registration/Login Required] Students identify segments and lines related to circles and the properties of a tangent to a circle.

Three circles are mutually tangent. Students are asked to find the total area of the circles plus the area inside where they meet. Students will need to know how to calculate the area of a circle, a sector of a circle, and an equilateral...

[Free Registration/Login Required] Students can adjust the size of the circle to explore the tangent lines. Click learn more to watch a video and click challenge me to answer a practice question.

The Clark University site shows and explains the graphs of the six trigonometric functions. It explains how to find an arbitrary angle measurement using trig. Also, it explains that sine and cosine functions are complementary.

Some friends are at the beach looking out onto the ocean on a clear day and they wonder how far away the horizon is. A second problem asks how far the horizon would be from the top of a mountain. Students must also answer a question...

Guide a mummy safely through the burial chambers of a pyramid as you solve length and area problems in basic to advanced geometry. There are four game zones that deal with circles and triangles, quadrilaterals, the Pythagorean Theorem,...

Hotmath provides 26 practice problems relating to conic sections. Each of the practice problems include a step-by-step guide for solving their conic.

Solve two challenging problems that apply properties of tangents to find the perimeter of a circumscribing shape.

Explains the basic concept of chords with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, students can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.

Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, young scholars can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.

Find the sine and cosine of special angles, which are angles whose trig values we can determine without the use of a calculator. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or...

The purpose of this task is to apply knowledge about triangles to calculate the sine and cosine of 30 and 60 degrees. Aligns with HSF-TF.A.3.

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...

In Spanish. Interactive activities online on various geometric and trigonometric concepts such as area, perimeter, secants, tangents, etc. A terrific resource for students. Site is organized acoording to shape. (triangle, quadrilaterals,...

This applet allows the user to create the graphs of sin, cos, and tan by moving a scroll bar. The user can watch the unit circle and the graph simultaneously to see how the two are related. The user may also choose to see the angle...

This section explores the Pythagorean Identity and how it applies to right triangles set inside unit circles, in terms of sine, cosine, and tangent functions.

In Spanish. This interactive unit introduces various geometric concepts which are intended to be tools for solving problems of tangencies between straight lines, circles and points.

A java applet that relates the unit circle to the graphs of the six trigonometric functions, complete with the values of the functions.

Learn about secants with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.

This site offers numerous activities for middle school and high school students to explore using Geometer's Sketch Pad.

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)...