Illustrative Mathematics
Lines of Symmetry for Triangles
What can symmetry tell us about triangles? After looking at four examples, learners will come to realize that lines of symmetry are different for equilateral, isosceles, and scalene triangles. Use this guided practice activity as an...
National Security Agency
Classifying Triangles
Building on young mathematicians' prior knowledge of three-sided shapes, this lesson series explores the defining characteristics of different types of triangles. Starting with a shared reading of the children's book The Greedy...
Illustrative Mathematics
Are These Right?
Is that a right triangle or a wrong triangle? Young mathematicians look at eleven different shapes and use a measuring tool of their choice to determine which triangles have right angles. Consider cutting out sets of the shapes to...
Illustrative Mathematics
All vs. Only Some
All shapes have certain defining attributes that set them apart from others. In order to understand this, young mathematicians look at examples and non-examples of triangles, rectangles, and squares, working as a whole class to create...
Illustrative Mathematics
Shape Sequence Search
Learning that size and orientation don't affect the classification of shapes is a big step for young mathematicians. Support children with developing this key understanding by looking at the array of shapes included in this resource. For...
Noyce Foundation
Lawn Mowing
This is how long we mow the lawn together. The assessment requires the class to work with combining ratios and proportional reasoning. Pupils determine the unit rate of mowers and calculate the time required to mow a lawn if they work...
McGraw Hill
Glencoe: Self Check Quizzes 2 Triangles
Use Glencoe's Math Course 2 randomly generated self-checking quiz to test your knowledge of a variety of triangle topics. Each question has a "Hint" link to help. Choose the correct answer for each problem. At the bottom of the page...
Math Open Reference
Math Open Reference: Triangle Quiz
Students are assessed on different types of triangles. Definitions of the triangles are included.
Houghton Mifflin Harcourt
Holt, Rinehart and Winston: Homework Help Independent Practice: Triangles
Get independent practice working with triangles. Each incorrect response gets a text box explanation and another try. Correct responses are confirmed.
Soft Schools
Soft Schools: Types of Triangles Quiz
The problems on this quiz give descriptions and properties of specific triangles. Students are expected to read the information and identify the triangle that is being described.
Khan Academy
Khan Academy: Recognizing Triangle Types
In this exercise, students practice recognizing triangle types. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.