Purple Math
Purplemath: Quadrants and Angles
Explains how to model angles in the x,y-plane, and demonstrates how to extend the concept of trig ratios to angles larger than 90 degrees.
Purple Math
Purplemath: Sectors, Areas, and Arcs
Explains formulas for areas of sectors of circles and lengths of arcs. Demonstrates how to use the formulas in each of degrees and radians.
Purple Math
Purplemath: The Unit Circle
Relates the unit circle to the method for finding trig ratios in any of the four quadrants. Demonstrates how the unit circle might be useful.
E-learning for Kids
E Learning for Kids: Math: Dojo: Area, Measurement, and Angle
Students will play learning games to explore area, measurement, and angles.
Government of Alberta
Learn Alberta: Exploring Angles Within a Triangle
This multimedia site offers a video [1:29] of how angles are important in the construction of bikes. Visit the interactive exercises to continue this beginner's guide to understanding angles in a triangle. Printable extended exercises...
Math2
Math2.org: Trigonometry Functions
A complete look at trig functions. From an "overview," page giving general definitions and important vocab words, to a listing of the 12 trig functions, to an explanation of the three modes used in trigonometry, to the procedures of how...
Math2
Math2.org: Trigonometry Tables
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)...
Scholastic
Scholastic: Dirtmeister's Science Reporters: Simple Machines: The Screw
Scholastic provides an in-depth description here of a simple machine called The Screw. Also provides a picture and several examples for understanding.
Math Words
Math Words: Cofunction Identities
This MathWords.com site, which is a glossary of math terms, shows the relationship in radians and degrees between sin and cos, tan and cot, and sec and csc.
The Math League
The Math League: Angles and Angle Terms: Acute Angles
This tutorial provides a basic definition and examples of acute angles.
The Math League
The Math League: Angles and Angle Terms: Complementary Angles
This tutorial provides a short definition of complementary angles.
The Math League
The Math League: Corresponding Angles
This tutorial provides a definition of corresponding angles and additional information is provided on angles.
The Math League
The Math League: Obtuse Angle
This tutorial on angles gives a basic definition of obtuse angles.
The Math League
The Math League: Angles and Angle Terms: Right Angle
This tutorial on angles presents a short definition of a right angle.
The Math League
The Math League: Angles and Angle Terms: Supplementary Angles
This tutorial on angles with definitions and examples, provides a definition of supplementary angles. At the top of the page is a series of links for additional information on related subjects.
Quia
Quia: Introduction to Angles
Use this website to practice angle definitions using a matching game format.
Quia
Quia: Introduction to Angles Flashcards
Use this website to practice angle definitions using a flash card format.
Quia
Quia: Introduction to Angles Concentration
Use this website to practice angle definitions using a concentration game format.
Quia
Quia: Introduction to Angles: Word Search
Use this website to practice angle definitions using a word search format.
National Council of Teachers of Mathematics
Nctm: Figure This: What's My Angle?
Do people with big hands have larger angles between their fingers? See if you can find the answer this question when you try this math challenge on estimating and measuring angles. Discover how understanding angles and geometric shapes...
ClassFlow
Class Flow: Polygons
[Free Registration/Login Required] This is a lesson on interior and exterior angles of polygons. This has an interactive piece as well as an assessment piece.
ClassFlow
Class Flow: Triangle Segments
[Free Registration/Login Required] In this flipchart, students use the interactive features of Activstudio to understand how to use the properties of perpendicular bisectors, angle bisectors, medians and altitudes of a triangle.
ClassFlow
Class Flow: Triangles and Angles
[Free Registration/Login Required] Classify angles by their side and angles. Find angles and measure in triangles.
Free Math Help
Free Math Help: Defined Terms
The lesson discusses commonly used geometric terms. Definitions and examples of a line segment, ray, and angle are included.