Math: Geometry: Angles and Triangles
Learn about angles and triangles. See examples of acute, obtuse, and right angles as well as equilateral, isosceles, and scalene triangles. Find out several rules of angles, triangles, and Pythagorean Theorem. Includes classroom activities, quizzes, and animated movies on triangles. There is a link to an eThemes Resource on shapes.
Grades
 4,
 5,
 6,
 7
Links

Types of Triangles Based on Angles
Practice recognizing types of triangles based on their angles measurements. Click on the "Next Lesson" link at the top to practice recognizing triangles by their sides' lengths and finding an angle.

Triangle Geometry
This site has extensive explanations of angles and triangles. Follow the links to view glossary definitions and see proofs of different theorems.

Enchanted Learning: Angles and Triangles
Read the definitions for the different types of angles and triangles, then try labeling the diagram. Click on "Answers" to see how you did. NOTE: The site includes ads.

edHelper: Angles
This printable worksheet has students identify what types of angles are shown.

edHelper: Angle Measurement
Students can practice measuring these angles.

BrainPOP: Geometry and Measurement
Watch three animated movies to learn about "Measuring Angles", "Types of Triangles", and "Similar Triangles". Choose these movies from the table and don't forget take quizzes and view fun activities. NOTE: The web site is available by subscription only.

BrainPOP: Algebra: Pythagorean Theorem
Click on the "Pythagorean Theorem" icon to watch a movie and learn how the theorem works. NOTE: The web site is available by subscription only.

Fact Monster: Triangles
Learn the different types of triangles and what type of angles they have. NOTE: The site includes popup and banner ads.

ThinkQuest: Isosceles and Equilateral Triangles
This studentcreated site has descriptions of the isosceles and equilateral triangles followed by an interactive quiz. Click on the "Special Triangles" link at the left to learn two theorems of right isosceles triangles. NOTE: The site has a link to a message board.

Polygons: Triangles
This site takes you stepbystep through the different types of triangles. NOTE: The site includes ads.

edHelper: Classify Triangles
Try to identify these different types of triangles.

SuccessLink: Furniture Design
This lesson plan from a Missouri teacher has students design furniture using triangles and other shapes.

Figure It Out!
This table game can help kids to learn how to identify different types of triangles.

Impossible Triangles
Test your knowledge of triangles and point out what is wrong with triangles on this page.

PBS: Peddling Petals
This classroom activity has students use triangles and rectangles to make patterns.

eThemes Resource: Math: Geometry: Shapes
These sites are about shapes including quadrilaterals and polygons. Includes definitions and examples of them in everyday life. There are interactive sites with games, manipulatives, and animated movies.
Education Standards
 ME
 MO
 AL