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.

In this section we will give a quick review of trig functions. We will cover the basic notation, relationship between the trig functions, the right triangle definition of the trig functions. We will also cover evaluation of trig...

Begin by watching this captivating video showing how the concepts of similarity and congruence are found in road signs. Following the video [1:27], an interactive applet allows students to resize, flip, move and rotate triangles to...

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.

[Free Registration/Login may be required to access all resource tools.] Calculate sine, cosine, and tangent functions using the sides of a right triangle.

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...

This is a excellent review lesson about trigonometric functions of any angle. Good examples here.

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.

The purpose of this task is to use the notion of similarity to define the sine and cosine of an acute angle. Aligns with G-SRT.C.6.

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.

Here is a site that clearly and thoroughly explains the trigonometric functions of acute angles within a right triangle. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point...

Learn about arcsine, arccosine, and arctangent, and how they can be used to solve for a missing angle in right triangles.

This site provides information on sine, cosine, and tangent. Lengths of the sides are discussed and many diagrams/tables are shown.

In addition to understanding the concept of similar right triangles and how they apply to trigonometric ratios, students explore a clinometer app, and discover how it can be used to test the mathematics underpinning trigonometry.

[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.

Solve word problems that involve general triangles using trigonometry. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Solve missing triangle measures using the law of cosines. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

This is an introductory lesson about the trigonometric function sine. Students will study several similar right triangles and the ratio of certain two sides in them.

Demonstrates how to use trig ratios to do simple solving of triangles.

This page provides a good explanation of how to solve oblique triangles (triangles containing no right angles.) The Law of Cosines section is about halfway of the way down the page.

[Free Registration/Login Required] This flipchart shows the basic relationships between trig functions and the sides and angles of a right triangle.

[Free Registration/Login may be required to access all resource tools.] Use the Pythagorean Theorem to determine if triangles are acute, obtuse, or right triangles.

[Free Registration/Login may be required to access all resource tools.] Find distance using right triangles and angles of elevation or depression.

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.