Khan Academy
Khan Academy: Angle Types
Determine if an angle is acute, right, or obtuse. A protractor is provided. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Alabama Learning Exchange
Alex: Angle Scavenger Hunt
In this instructional activity, 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...
McGraw Hill
Glencoe Mathematics: Online Study Tools: Triangles and Angles
This site gives a short interactive quiz which allows students to self-assess their understanding of the concept of triangles and angles.
The Math League
The Math League: Figures and Polygons
This site provides definitions of different types of polygons and figures.
Oswego City School District
Regents Exam Prep Center: Geometry Vocabulary Resources
A list of geometry definitions and a matching activity.
Beacon Learning Center
Beacon Learning Center: Triangles Side by Side
This comprehensive web lesson describes how to classify triangles by their angle and side measurements. It provides real-world examples and exercises for students to practice the skill.
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: Angles Votes
[Free Registration/Login Required] Using this flipchart, students will be able to identify various angles based on mathematical criteria. Questions are related to right, acute, and obtuse angles.
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...
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...
Homeschool Math
Homeschool Math: Triangles
This lesson plan provides students with an opportunity to practice drawing and measuring triangles and angles. It also shows pictures and gives definitions of each type of angle and triangle.
Math Open Reference
Math Open Reference: Triangles
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.
The Math League
The Math League: Figures and Polygons
This website has basic definitions for most polygons, regular and irregular.
University of Saskatchewan (Canada)
University of Saskatchewan: Trigonometric Functions
This site examines the six trigonometric functions from a right triangle point of view. Provides information, examples, and lots of exercises for understanding.
Mr. Martini's Classroom
Mr. Martini's Classroom: Basic Geometry: Points, Lines, and Angles
Students can review basic geometric terms using these self-check, multiple choice questions. Three levels of questions are provided.
CK-12 Foundation
Ck 12: Converse of the Pythagorean Theorem
[Free Registration/Login may be required to access all resource tools.] Learn about the converse of the Pythagorean Theorem and some of its applications. Also explains how to identify acute and obutse triangles through the use of the...
Oswego City School District
Regents Exam Prep Center: Triangle Information
This Oswego City School District site from the Regents Exam Prep Center provides an explanation of the classifications of triangles both by sides and by angles. Pictures are also included.
Khan Academy
Khan Academy: Area of Triangles
Practice finding the area of right, acute, and obtuse triangles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Quia
Quia: Geometric Terms Word Search
Do you need practice remembering or learning different geometry vocabulary words and definitions? This word search is the web site for you! There is a link to a list of terms with definitions you can click if you want to see if you are...
CK-12 Foundation
Ck 12: Elem Math: Classifying Triangles Within Composite Figures
[Free Registration/Login may be required to access all resource tools.] In this learning module, students are presented with a composite figure and must identify the types of triangles within it. An accompanying video demonstrates a...
Math Is Fun
Math Is Fun: Interactive Triangles
This is an excellent tool for students to explore how changes in the size of a triangle's sides or angles affect its appearance. Different types of triangles and angles are presented.
University of Georgia
University of Georgia: Inter Math: Oblique
This site describes the concept of oblique, expressing both triangles and three dimensional solids. Be sure to use the links to related terms, everyday examples, challenging problems, more information, and the interactive check point...
CK-12 Foundation
Ck 12: Elem Math: Classifying All Types of Triangles by Lengths of Sides
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on classifying triangles based on length of sides.