Curated OER
Isosceles Triangles
In need of a fun way to define an isosceles triangle? This activity has learners fold a paper in half and then cut it to create an isosceles triangle. They determine the line of symmetry by folding the triangle in half and then use the...
Exploratorium
The Four-Square Quilt
Youngsters recognize that triangles can be combined together to make various shapes. The learning activity provides a series of seven steps that engage children in applying transformations to triangles. Pupils use a quilt template and...
Primary Resources
Different Types of Triangles
Are there different types of triangles? Yes there are, and this presentation describes each by its properties or characteristics. Right, equilateral, isosceles, and scalene are all shown and defined. The presentation isn't particularly...
Curated OER
Triangles
In this geometry learning exercise, students will answer questions to determine if a shape is a triangle and if so, what type of triangle.
Curated OER
Triangles
Fourth graders participate in three experiments to gain understanding of triangles. For this triangles lesson, 4th graders use pipe cleaners to create bubble pipes, basketball hoops and bingo cards to display the characteristics of...
Curated OER
Triangle Foldable
In this math worksheet, students cut out six cards with the names of different triangles. Triangles include equilateral, scalene, and isosceles.
Curated OER
Triangle Puzzler
In this math worksheet, students analyze a chart and identify the names of 9 types of triangles. Students also find as many kinds of triangles they can in a given figure.
Curated OER
Drawing a Triangle with Cabri Junior
Learners draw triangles on their graphing calculators using the Cabri Junior application. In this graphing calculator lesson plan, students follow step by step directions to create triangles on their calculator. They identify the type of...
Curated OER
Identifying Triangles
In this triangles practice worksheet, students respond to 4 questions that require them to identify the pictured triangles as acute, right, obtuse, scalene, isosceles, or equilateral triangles.
Curated OER
Identifying Triangles
In this triangles practice worksheet, students respond to 4 questions that require them to identify the pictured triangles as acute, right, or obtuse triangles.
Curated OER
Classifying Shapes Using Venn Diagrams
In this classifying shapes using Venn diagrams worksheet, students draw examples of isosceles, right, and equilateral triangles in the proper sections of the first graphic organizer. They draw polygons, both regular and quadrilaterals,...
Curated OER
Triangles Word Search
In this word search worksheet, students locate 7 types of triangles. Triangles include isosceles, acute, equilateral, right, and obtuse.
National Council of Teachers of Mathematics
The Math Forum: Triangle Formulas
Investigate the geometric definitions of triangles, focusing upon equilateral, isosceles, right, and scalene with detailed drawings and appropriate formulas for each. This site has links to more information on triangles.
Oswego City School District
Regents Exam Prep Center: Angles and Triangles
On this site a viewer can learn about the different types of triangles, and categorized by either angles or sides. Tutorials are also included for interior and exterior angles of triangles. A teacher resource page includes a lesson plan...
Cuemath
Cuemath: Obtuse Triangle
In this mini-lesson, learn about obtuse triangles including the obtuse triangle definition, sides, properties, examples, and other fun facts related to it.
Cuemath
Cuemath: Triangles
Explore everything about triangles. Learn about the different types, important properties, and how to find its area and perimeter. Check out the solved examples and interactive questions for better understanding.
E-learning for Kids
E Learning for Kids: Math: Music: 2 D Shapes
Kyan is an African villager. Can you help him name and define different parts of shapes?
E-learning for Kids
E Learning for Kids: Math: Group of Pyramids: 2 D Shapes
Abeni works at the pyramids. Visit her and find out more about circles and triangles.
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.
AAA Math
Aaa Math: Types of Triangles Based on Angles
Students can practice classifying triangles based on angle measurements through a series of self-check exercises and timed learning games.
AAA Math
Aaa Math: Types of Triangles Based on Sides
Students can practice classifying triangles based on side lengths through a series of self-check exercises and timed learning games.
Rice University
Rice University: Geometry Online: Impossible Triangles
This site has an activity that displays several impossible triangles. The rules for triangles are also displayed. The student has to determine which rule has been violated for each impossible triangle.
Scholastic
Scholastic: Study Jams! Math: Geometry: Classify Triangles
After completing the lesson on classifying triangles, you can sing along with karaoke and test your knowledge.
K-5 Math Teaching Resources
K 5 Math Teaching Resources: Isosceles Triangles on the Geoboard [Pdf]
Students will learn about isosceles triangles. Materials needed include circular geoboards, rubber bands, circular geoboard paper and rulers.