[Free Registration/Login may be required to access all resource tools.] In this lesson students apply the Exterior Angles Theorems. Students examine guided notes, review guided practice, watch instructional videos and attempt practice...

Students may use this computer applet to explore angle sums of triangle, quadrilaterals, pentagons and hexagons.

Practice using your graphing calculator for drawing and labeling points, lines, planes, and angles. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly under each...

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

Learn how to add vectors. Drag vectors onto a graph, change their length and angle, and sum them together. The magnitude, angle, and components of each vector can be displayed in several formats.

Learn how to add vectors. Drag vectors onto a graph, change their length and angle, and sum them together. The magnitude, angle, and components of each vector can be displayed in several formats.

Given the sum of a pair of angles and the algebraic expressions that represent them, form and solve an equation. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

The goal of this task is to provide a geometric explanation for the relationship between the sine and cosine of acute angles. In addition, students will need to think about the sine and cosine as functions of an angle in order to reason...

This site gives a definition of angle of rotation and provides some examples. There is also an interactive activity in which a JavaSketchPad page is provided for you to explore rotations. In addition, be sure to follow the links to...

The purpose of this task is to gain experience drawing and measuring angles, developing an understanding of the additive structure of angles. Aligns with 4.MD.C.7.

This very basic website gives a clear, simple explanation of the sum of angles on a straight line that when put together form a straight angle.

Finding the third angle of a triangle becomes easier by the explanation and examples presented.

Find the trigonometric values of various angles that (while they are not special angles) can be expressed as the sum or difference of special angles. Students receive immediate feedback and have the opportunity to try questions...

Find the trig values of sums of angles whose individual trig values are known. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

In this tutorial, examine the effect of forces acting at angles to the horizontal, such that the force has an influence in two dimensions- horizontally and vertically.

Find a quick, concise explanation of the Angle Sum Theorem. A step by step explanation of the proof is included to help you understand the theorem.

In this instructional activity, middle schoolers explore different polygons by drawing them, measuring angles, and manipulating interactive sketches to find the angle sum for any polygon. Students also explore the angle measures in...

This tutorial offers formulas and explanations on trigonometric addition formulas and features an easy way to remember the sine and cosine addition formulas using matrices.

The goal of this task is to have students derive the addition and subtraction formulas for cosine and tangent, and the subtraction formula for cosine, from the sum formula for sine. Aligns with F-TF.C.9.

An interesting junkyard of geometry findings where people are free to add their own findings and sift through others' interesting additions.

[Free Registration/Login Required] Learn about adding two vectors together by components in the context of a GPS-style city map. Adjust magnitude and angles in the two vectors to simulate the driverless car. Examples taking this concept...

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

The Northeast Parallel Architectures Center, Syracuse University, provides a review and tutorial site on trigonometry. The information is in-depth and can be accessed by clicking on the various links in the outline.

Use Glencoe's Math Course 2 randomly generated self-checking quiz to test your knowledge of a variety of triangle topics. Each question has a "Hint" link to help. Choose the correct answer for each problem. At the bottom of the page...