Lesson Planet
Search educational resources
  • Sign In Try It Free
  • AI Teacher Tools
    • Discover Resources Search reviewed educational resources by keyword, subject, grade, type, and more
    • Curriculum Manager (My Content) Manage saved and uploaded resources and folders To Access the Curriculum Manager Sign In or Join Now
    • Browse Resource Directory Browse educational resources by subject and topic
    • Curriculum Calendar Explore curriculum resources by date
    • Lesson Planning Articles Timely and inspiring teaching ideas that you can apply in your classroom
    • Our Story
    • Frequently Asked Questions
    • Testimonials
    • Contact Us
  • Pricing
  • School Access
    • Your school or district can sign up for Lesson Planet — with no cost to teachers
      Learn More
  • Sign In
  • Try It Free

Hi, what do you want to do?

Create a lesson plan
Create a lesson plan
Generate resources with 80+ AI teacher tools
Generate resources with 80+ AI teacher tools
Search 200,000 instructional videos
Search 200,000 instructional videos
Find a teaching resource
Find a teaching resource
Classifying Triangles WorksheetClassifying Triangles Worksheet
Publisher
Curated OER
Curator Rating
Educator Rating
Not yet Rated
Worksheet

Classifying Triangles

Curated and Reviewed by Lesson Planet

In this classifying triangles worksheet, learners explore given lengths or angle measurements and then classify each triangle as isosceles, scalene or equilateral. They also determine if the triangle may be right, acute or obtuse. This three-page worksheet contains 20 problems. Answers are provided on the last page of the worksheet.

28 Views 137 Downloads
Concepts

acute angles, angles, equilateral, isosceles triangles, triangles, obtuse angles, scalene, triangle classification

Additional Tags

acute, classifying triangles, equilateral, isosceles, obtuse, right, scalene, math
Show More Show Less

Resource Details

Grade
8th - 10th
Subjects
Math
1 more...
Resource Types
Worksheets
2 more...
Audiences
For Teacher Use
1 more...
Usage Permissions
Fine Print: Educational Use

See similar resources:

Lesson Plan

Special Right Triangles and Right Triangle Trigonometry

Odell Education
Right triangles are so special! Use special right triangles to discover the trigonometric ratios. Pairs construct special right triangles and find the values of the ratios of the sides. In the process, they discover the ratios stay the...
9th - 11th Math
CCSS: Adaptable
Lesson Plan

Toothpick Triangles

Curated OER
Students draw a chart (included in the lesson) to use with their investigation. They review terminology of triangles and receive toothpicks to use in the lesson. Beginning with three toothpicks, students form a triangle. They complete...
4th - 8th Math
Instructional Video

Special Right Triangle 45-45-90: Lesson

CK-12 Foundation
Square roots connect squares and right triangles. Using the Pythagorean Theorem, the video shows the relationship between the sides and hypotenuse of a 45-45 right triangle. The portion of a larger geometry playlist applies the...
4 mins 8th - 11th Math
Instructional Video

Classifying Triangles: Lesson

CK-12 Foundation
That's correct, it is right and scalene. The video introduces the two methods for classifying triangles, sides, and angles. A resource in the playlist for basic geometry provides the definitions for each of the classifications.
5 mins 4th - 8th Math
CCSS: Adaptable
Instructional Video

What are Equilateral, Isosceles, and Scalene Triangles?

Curated OER
Triangles are classified by their angle measurement as well as by the length of their sides. Here are some names that identify the types of triangles: right, isosceles, equilateral, scalene, obtuse, and acute. Watch this video to learn...
6 mins 5th - 8th Math
Instructional Video

How Do You Find Missing Angles in an Isosceles Triangle Using Right Triangles?

Curated OER
Given an isosceles triangle, and the value of one angle, find the missing values. There are some special properties about isosceles triangles. Use the triangle sum theorem to solve this problem. Watch this video to see how the instructor...
4 mins 6th - 8th Math
Lesson Plan

Identifying a Triangle by its Sides and Angles

Texas Instruments
Identify triangles by their angle measures and side lengths by looking at and measuring angle measures and side lengths. Use Cabri Jr. to construct various triangles, then manipulate the construction to create the 6 types of triangles,...
9th - 12th Math
CCSS: Designed
Lesson Plan

The Pythagorean Theorem and Classifying Triangles

Curated OER
Through the examination of the relationship between the lengths of the sides of a triangles high schoolers will learn the classification of triangles (acute, right, or obtuse).
9th - 12th Math
CCSS: Designed
Lesson Plan

What You Know About the Bermuda Triangle?

Alabama Learning Exchange
Get lost in the classifications. Using the backdrop of the Bermuda Triangle, pupils classify it by angle and side measures. They also learn information about the triangle and its history.
9th - 12th Math
CCSS: Designed
Interactive

Pythagorean Theorem to Classify Triangles: Missing Angles

CK-12 Foundation
Learn to use the Pythagorean Theorem with non-right triangles. Pupils use the interactive to discover the relationship between the lengths of sides for acute and obtuse triangles. They compare the squares of the sides of the triangles to...
8th - 12th Math
CCSS: Designed
Try It Free
© 1999-2026 Learning Explorer, Inc.
Teacher Lesson Plans, Worksheets and Resources

Sign up for the Lesson Planet Monthly Newsletter

Open Educational Resources (OER)

  • Health
  • Language Arts
  • Languages
  • Math
  • Physical Education
  • Science
  • Social Studies
  • Special Education
  • Visual and Performing Arts
View All Lesson Plans

Discover Resources

  • Our Review Process
  • How it Works
  • How to Search
  • Create a Collection

Manage Curriculum

  • Edit a Collection
  • Assign to Students
  • Manage My Content
Contact Us Site Map Privacy Policy Terms of Use