Khan Academy
Khan Academy: Draw Right, Acute, and Obtuse Angles
Create an acute, right, or obtuse angle using a given vertex. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Math Planet
Math Planet: Geometry: Measure and Classify an Angle
Explains the terms and symbols used to discuss line angles, what an angle is, and the types of angles. Includes short video lesson demonstrating how to use a protractor to measure an angle. [0:57]
Alabama Learning Exchange
Alex: Geometric Man
The learners will explore angles, rays, line segments, perpendicular lines, parallel lines, and two-dimensional figures through the use of the book Shape Up! Fun With Triangles and Other Polygons by David A. Adler. They will also...
Alabama Learning Exchange
Alex: Angle Scavenger Hunt
For this lesson, students will explore straight, right, acute, and obtuse angles. Students will go on a scavenger hunt throughout the school to search for examples of these types of angles. The students will use digital cameras to record...
Scholastic
Scholastic: Study Jams! Math: Geometry: Classify Angles
Watch and learn how to classify angles then test your knowledge.
Khan Academy
Khan Academy: Angle Basics
Determine which angle has a greater measure by looking at the size of the opening between the angle's rays.
Khan Academy
Khan Academy: Angle Types
Determine if an angle is acute, right, or obtuse. A protractor is provided.
Khan Academy
Khan Academy: Angles in Circles
Practice measuring angles using a circle protractor, solve problems about angles as part of a circle.
Homeschool Math
Homeschool Math: Lines, Rays, and Angles
This fourth-grade geometry lesson teaches the definitions for a line, ray, angle, acute angle, right angle, and obtuse angle. We also study how the size of the angle is ONLY determined by how much it has "opened" as compared to the whole...
Quia
Ixl Learning: Types of Angles
Brush up on your math skills pertaining to types of angles then try some practice problems to test your understanding.
Math Is Fun
Math Is Fun: Right Angle
This very basic website gives a clear, simple explanation of what a right angle is.
Math Is Fun
Math Is Fun: Definition of Bisector
A clear definition and drawing of a bisector, a line that divides one angle into two.
The Math League
The Math League: Rays
This website gives a very brief explanation and example of rays.
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: Right Angles
[Free Registration/Login Required] This flipchart is designed to introduce the student to the concept of the right angle and to give the student practice in identifying right angles as well as measuring angles with a protractor.
Math Is Fun
Math Is Fun: Acute Angle
This very basic website gives a clear, simple explanation of what an acute angle is.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Angle Basics
Find a quick, concise explanation of angles and types of angles. Several examples are given to help you understand how angles are formed and the different types of angles.
ClassFlow
Class Flow: All About Angles
[Free Registration/Login Required] This flipchart gives an introduction to angles, reading a protractor, naming and classifying angles. It also includes opportunities to practice these skills. The lesson is aligned with the 5th grade...
ClassFlow
Class Flow: Angle Tester
[Free Registration/Login Required] This flipchart reviews right, acute and obtuse angles with students. An Activote review is included at the end.
ClassFlow
Class Flow: Angle This Way
[Free Registration/Login Required] Students will identify right, acute and obtuse triangles using many interactive tools available in ACTIVstudio 3.0. Students will be engaged using a magnifier tool, the fill tool, and drag and drop and...