Teach Your Students How to Classify Triangles 

Don’t be fooled! While they may all have three sides and three internal angles, not all triangles are created equally! There are actually several different types of triangles, three of these being acute triangles, right triangles and obtuse triangles.

This set of three worksheets has been designed to help your students classify triangles based on the size of their internal angles. The worksheets contain a variety of different activities, such as:

• Completing the table by adding the correct triangle under the correct heading
• Identifying the triangles that are being described by each statement
• Answering true or false questions about triangle 
• Completing the table by drawing examples of each triangle type
• Completing the cloze passages about each triangle type
• Completing the table by filling in the attributes of each triangle type
• Identifying triangles that have been incorrectly sorted
• Solving riddles about triangles

The resource download includes:

• 3 x different classifying and sorting triangles worksheets
• Answer key

Students can complete the worksheets independently, in pairs or during small group time with the teacher. Different groups can be assigned different pages, or students can complete all three (depending on their level of confidence with the content).

Tips for Differentiation and Scaffolding 

If you are looking for ways to differentiate this activity to meet the needs of all learners, try out these suggestions:

• Challenging Your High-Flying Students – Challenge your more-confident students to create their own classifying activity for acute, right and obtuse triangles. Have the students swap their activities with a partner for them to complete.
• Support Your Less-Confident Students –  Some students may benefit from scaffolding materials to assist them while sorting the triangles. Provide examples of each triangle type with all the attributes labeled. Students may also benefit from using a protractor to help them determine the size of each angle.

Download This Triangles Worksheet

Use the dropdown icon on the Download button to select between the editable Google Slides or easy-print PDF version of this resource.

As this resource contains an answer sheet, we recommend printing one copy of the entire file, then removing the student worksheets for photocopying.

Alternatively, project the worksheets on a screen and work through them as a class for a paperless lesson!

This resource was created by Lorin Davies, a teacher in Texas and a Teach Starter collaborator.

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