K12 Reader
Classifying Triangles
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...
K-5 Math Teaching Resources
Triangle Pack
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...
McGraw Hill
Triangles
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...
Virginia Department of Education
Classifying Angles
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...
Willow Tree
Common Geometric Figures
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.
Bowland
Rods and Triangles
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...
Scholastic
Study Jams! Classify Triangles
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...
PBS
Accessible Shapes
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....
Houghton Mifflin Harcourt
Unit 6 Math Vocabulary Cards (Grade 5)
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...
Los Angeles County Office of Education
Assessment For The California Mathematics Standards Grade 4
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,...
Alabama Learning Exchange
What You Know About the Bermuda Triangle?
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.
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...
Mathematics Vision Project
Module 5: Modeling with Geometry
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...
Concord Consortium
Three Rubber Bands
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...
Raytheon
Understanding Triangles
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...
Khan Academy
Khan Academy: Identify Triangles by Side Lengths
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.
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 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.
Illustrative Mathematics
Illustrative Mathematics: 4.g Lines of Symmetry for Triangles
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.
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.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.4 Triangles
Explore and measure a variety of triangles.
E-learning for Kids
E Learning for Kids: Math: Riksjas, Toek Toek: Polygons
Explore polygons with Wang, a ricksha puller. Answer his questions and he will give you a free ride!
Rice University
Rice University: Cynthia Lanius: Hidden Polygon Activity
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.