Printables
K-5 Math Teaching Resources

Triangle Pack

For Teachers 4th - 6th Standards
With so many different types of triangles, it can be a challenge for young mathematicians to keep them all straight. Luckily this set of printable triangles is here to engage children in comparing and sorting triangles by their...
Lesson Plan
Alabama Learning Exchange

What You Know About the Bermuda Triangle?

For Teachers 9th - 12th Standards
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.
Handout
McGraw Hill

Triangles

For Students 4th - 7th Standards
After reviewing characteristics of seven types of triangles, young geometers discover how to find the missing angle of a triangle. Then, they practice identifying triangles, find missing angles, and find missing side lengths of...
Interactive1:45
Scholastic

Study Jams! Classify Triangles

For Students 5th - 8th Standards
Jam on with this multi-faceted activity teaching triangle classification. Start with a learner-paced lesson describing the different qualities of triangles and follow with a fun karaoke session. Also provided are two types...
Worksheet
K12 Reader

Classifying Triangles

For Students 2nd - 3rd Standards
Bring math and reading informational text together with a reading comprehension lesson. After kids read about isosceles, scalene, and equilateral triangles, they answer five comprehension questions to demonstrate how they can use context...
Assessment
Bowland

Rods and Triangles

For Teachers 6th - 9th
Scholars explore triangles with rods of different lengths. Using rods of 2, 4, 6, 8, and 10 cm class members build as many different types of triangles as they can. They also describe properties of these triangles and determine...
Lesson Plan
National Security Agency

Classifying Triangles

For Teachers 4th - 8th Standards
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...
Worksheet
Raytheon

Understanding Triangles

For Students 6th - 8th
In this understanding triangles activity, students read 6 pages of examples and explanations about identifying triangles, determining length of sides and degrees of angles, including the hypotenuse, then answer 28 questions, answers...
Lesson Plan
Willow Tree

Common Geometric Figures

For Students 8th - 11th Standards
Geometry could be called the study of figures. An overview of the figures found in a typical geometry course contains a study of different triangles, quadrilaterals, and regular polygons. 
Assessment
Concord Consortium

Three Rubber Bands

For Students 7th - 12th Standards
Stretch your mind about triangles. Given a triangle, scholars consider a smaller triangle formed when they stretch three rubber bands from each vertex to the opposite side. They determine the ratios of the areas and perimeters of the...
Unit Plan
Mathematics Vision Project

Module 5: Modeling with Geometry

For Students 9th - 12th Standards
Solids come in many shapes and sizes. Using geometry, scholars create two-dimensional cross-sections of various three-dimensional objects. They develop the lesson further by finding the volume of solids. The module then shifts...
Unit Plan
Virginia Department of Education

Classifying Angles

For Teachers 4th - 8th Standards
Don't be obtuse, this geometry unit is the just the right resource for educating the acute young minds in your class. From classifying and measuring angles, to determining the congruence of shapes, this...
Unit Plan
PBS

Accessible Shapes

For Teachers 6th - 8th Standards
All the 2-D and 3-D measurement work you need is in one location. Divided into three sections, the geometry lesson plans consist of visualization of three dimensions, classifying geometric figures, and finding surface area and volume....
Assessment
Los Angeles County Office of Education

Assessment For The California Mathematics Standards Grade 4

For Students 4th Standards
Have scholars show what they know with a 20-page assessment aligned to the California State Standards. The test covers concepts such as large and whole numbers, all four mathematical operations, fractions, decimals, geometric figures,...
Printables
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Houghton Mifflin Harcourt

Unit 6 Math Vocabulary Cards (Grade 5)

For Students 5th Standards
Acute angles, nets, and vertices are only a few terms that a set of flash cards includes. Among the 108 cards, two types are available; word cards printed in bold-faced lettering, and corresponding definition cards equipped with an...
eBook
CK-12 Foundation

Ck 12: Interactive Geometry: 1.4 Triangles

For Students 9th - 10th Standards
Explore and measure a variety of triangles.
Unknown Type
McGraw Hill

Glencoe Mathematics: Online Study Tools: Triangles and Angles

For Students 9th - 10th Standards
This site gives a short interactive quiz which allows students to self-assess their understanding of the concept of triangles and angles.
Unit Plan
Khan Academy

Khan Academy: Identify Triangles by Side Lengths

For Students 3rd - 5th Standards
Practice identifying triangles by their side-lengths as equilateral, isosceles, or scalene. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Unit Plan
CK-12 Foundation

Ck 12: Elem Math: Classifying Triangles Within Composite Figures

For Students 3rd - 5th Standards
[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...
Unit Plan
Math Open Reference

Math Open Reference: Triangles

For Students 9th - 10th Standards
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.
Activity
Illustrative Mathematics

Illustrative Mathematics: 4.g Lines of Symmetry for Triangles

For Teachers 3rd - 5th Standards
The division of triangles into scalene, isosceles, and equilateral can be thought of in terms of lines of symmetry. Aligns with 4.G.A.3.
Unit Plan
E-learning for Kids

E Learning for Kids: Math: Riksjas, Toek Toek: Polygons

For Students 5th - 6th
Explore polygons with Wang, a ricksha puller. Answer his questions and he will give you a free ride!
Activity
Rice University

Rice University: Cynthia Lanius: Hidden Polygon Activity

For Students 4th - 7th Standards
On this site students are instructed to locate different types of polygons on triangle grid paper. This page can be printed so that students can actually draw them. It also gives a definitions link for each polygon.