Better Lesson
Better Lesson: Finding Angles
The three types of angles, right, acute, and obtuse, exist in our everyday surroundings. Students find these angles using classroom items.
CK-12 Foundation
Ck 12: Geometry: Angles Study Guide
This study guide on angles covers key vocabulary, ways to name angles, how to measure them, the Protractor Postulate and the Angle Addition Postulate, types of angles, congruent angles, angle bisectors, and angle pairs. It is available...
CK-12 Foundation
Ck 12: Geometry: Lines and Angles Study Guide
This study guide on lines and angles covers key terminology; line notation; parallel, perpendicular, and skew lines; and postulates and theorems about lines. It is available for download with free registration.
Scholastic
Scholastic: Study Jams! Math: Geometry: Classify Angles
Watch and learn how to classify angles then test your knowledge.
Khan Academy
Khan Academy: Angle Relationships With Parallel Lines
Find missing angles given two parallel lines and a transversal.
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.
National Council of Teachers of Mathematics
Nctm: Illuminations: Pi Fight
Become comfortable with using both radians and degrees.
Illustrative Mathematics
Illustrative Mathematics: 4.g Defining Attributes of Rectangles & Parallelograms
At early stages of understanding of geometric shapes, 4th graders describe shapes, but do not yet characterize shapes by their properties. One example of a misconception students have at this stage is that a rectangle has two short sides...
Better Lesson
Better Lesson: Differences With Shapes
Differences between shapes are determined through measurement skills.
Better Lesson
Better Lesson: What Makes a Shape? Analyzing and Script Writing
Third graders will use the bat houses we built as examples of various quadrilaterals.
Shodor Education Foundation
Shodor Interactivate: Image Tool
Measure angles, distances, and areas in several different images (choices include maps, aerial photos, and others). A scale feature allows the user to set the scale used for measuring distances and areas.
Math Open Reference
Math Open Reference: 30 60 90 Triangle
Learn about the 30-60-90 triangle with this helpful reference tool. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Radians
Learn about radians with this helpful reference tool. Provides a detailed definition, examples, and an interactive activity that enhance further explanation. Includes links to related topics.
Calculator Soup
Calculator Soup: Angle Conversion Calculator
Convert units of angles by entering the value to convert and the from and to units.
Geometry Help
Geometry Help: Arcs, Angles, and Sectors
Explains the basic concept of arcs, angles, and sectors with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Khan Academy
Khan Academy: Angles Lesson
Learning module with desciptions, examples and practice problems about all angle types.
Math Open Reference
Math Open Reference: Congruent
Learn about congruent with this handy reference guide. Provides a detailed definition and examples that enhance further explanation. Includes links to related topics.
Better Lesson
Better Lesson: Introduction to Angles
See this lesson to help students to learn about angles and identify the number of angles in 2D shapes. Lesson plans includes introductory activity, guided practice, and independent practice.
Homeschool Math
Homeschool Math: Lines, Rays, and Angles
This fourth-grade geometry instructional activity 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...
Khan Academy
Khan Academy: Draw Right, Acute, and Obtuse Angles
Create an acute, right, or obtuse angle using a given vertex.
CK-12 Foundation
Ck 12: Algebra Ii: 4.5 Graphing Sine and Cosine
This section explores the graphs of sine and cosine functions. It investigates how these graphs are related to coordinates for different angles in a unit circle.
Cuemath
Cuemath: Adjacent
Let's read about the word of adjacent, look at examples, and learn how angles can be adjacent. Check out the interesting examples to know more about this lesson and try your hand at solving a few interactive questions at the end of the...
OER Commons
Oer Commons: Gallery Problems Exercise
Students who have a clear understanding of the previous lessons can work on gallery problems of their choosing. This can be used as a good review or assessment.