Search Triangle Educational Resources

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41 filtered results
Triangles
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2D and 3D Shapes
2D and 3D Shapes
Worksheet
2D and 3D Shapes
Boost your child's understanding of geometry dimensions with this worksheet that challenges her to match 2D and 3D Shapes.
1st grade
Math
Worksheet
Geometry 2
Geometry 2
Guided Lesson
Geometry 2
Geometry in kindergarten involves the basics of measurement, shapes, and spatial reasoning. Designed and reviewed by teachers, this guided lesson gives kids an overview of these concepts with clear instruction and engaging exercises. Geometry practice in kindergarten can help bolster the skills needed for higher-level concepts in the later grades. You can give kids even more practice by downloading and printing the accompanying worksheets.
Kindergarten
Math
Guided Lesson
Geometry 4
Geometry 4
Guided Lesson
Geometry 4
This guided geometry lesson takes second graders on an exploration of 2D and 3D shapes. Kids will learn how to sort shapes, as well as partition them into halves, quarters and thirds. Tangrams are also featured within the exercise in order to give kids practical ways of practicing their new geometry skills. For more printable practice, try the geometry worksheets recommended by our curriculum advisors to accompany this lesson.
2nd grade
Math
Guided Lesson
Geometry 3
Geometry 3
Guided Lesson
Geometry 3
First grade geometry covers basic shapes, as well as an introduction to 3D shapes. Our team of curriculum experts designed the following guided lesson, which provides an overview of first grade geometric concepts and gives kids lots of opportunities for practice. If your child needs more support in a different format, check out the suggested first grade geometry worksheets.
1st grade
Math
Guided Lesson
Basic Shapes
Basic Shapes
Worksheet
Basic Shapes
Bust out those crayons, it's time to test your knowledge of basic shapes! Have your first grader sort out these shapes by color.
1st grade
Math
Worksheet
Counting 2
Counting 2
Guided Lesson
Counting 2
In this lesson, kindergarteners will be given the chance to focus on their counting skills with engaging exercises and guided instruction. Just as identifying the letters of the alphabet is a precurser to reading, so is counting to developing math fluency. Soon, your child will learn that the numbers they are counting have associated values, so the more practice they can get with counting the better.
Kindergarten
Math
Guided Lesson
Second Grade Fall Review Packet - Week 4
Second Grade Fall Review Packet - Week 4
Workbook
Second Grade Fall Review Packet - Week 4
This final installment of our Second Grade Fall Review Packet offers five more days of engaging activities that will prepare incoming second graders for a new year of learning.
2nd grade
Social studies
Workbook
Shapes in Pictures: Secret Garden
Shapes in Pictures: Secret Garden
Worksheet
Shapes in Pictures: Secret Garden
Here's a worksheet that shows kids how shapes can be found in real things by asking them to find and count all the different shapes in a picture of a garden.
1st grade
Math
Worksheet
Shapes From Every Angle
Shapes From Every Angle
Workbook
Shapes From Every Angle
Get in shape for geometry! From 2D to 3D, polygons to prisms, your child will soon be a shape master. After a review of important terms and concepts, he will practice identifying real world shapes.
1st grade
Math
Workbook
Dive Into Data
Dive Into Data
Workbook
Dive Into Data
Math isn't just adding and subtracting—it's about making sense of numbers and information. Practice with calendars and different types of graphs to help your child dive into data!
1st grade
Math
Workbook
Glossary: Composing Shapes
Glossary: Composing Shapes
Worksheet
Glossary: Composing Shapes
Use these this glossary with the EL Support Lesson: Composing Shapes.
1st grade
Math
Worksheet
Shape Match
Shape Match
Worksheet
Shape Match
Help your child practice his skills in geometry with this printable worksheet, which asks him to name the different shapes.
1st grade
Math
Worksheet
Spider Web Shapes
Spider Web Shapes
Activity
Spider Web Shapes
Take the spookiness out of spiders with this web-making activity! Your child will practice talking about and creating shapes in this Halloween craft, and learn about spiders along the way.
Preschool
Math
Activity
Shape Challenge: Find the Different Shapes!
Shape Challenge: Find the Different Shapes!
Worksheet
Shape Challenge: Find the Different Shapes!
A fun intro to geometry, this first grade math worksheet will help your child practice shape recognition and classification.
1st grade
Math
Worksheet
How Many Triangles Can Be Created?
How Many Triangles Can Be Created?
Worksheet
How Many Triangles Can Be Created?
Students explore the relationships between the side lengths and angle measures of triangles in this seventh-grade geometry worksheet!
7th grade
Math
Worksheet
Shape Chart
Shape Chart
Worksheet
Shape Chart
I spy with my little eye... some real-life shapes! Get your child to recognize shapes all around him by filling in this shape chart.
1st grade
Math
Worksheet
Triangle Sort
Triangle Sort
Worksheet
Triangle Sort
Build student understanding of the defining attributes of triangles with this sorting activity. Students will cut out different shape cards and sort them into examples and non-examples of triangles.
1st grade
Math
Worksheet
Constructing Triangles Given Conditions
Constructing Triangles Given Conditions
Worksheet
Constructing Triangles Given Conditions
Help students hone their geometry skills with this seventh-grade math worksheet all about creating triangles given specific information.
7th grade
Math
Worksheet
Plane and Solid Shapes
Plane and Solid Shapes
Worksheet
Plane and Solid Shapes
Challenge your young mathematician with some solid shapes like cubes, pyramids, prisms and cones!
1st grade
Math
Worksheet
Vocabulary Cards: Composing Shapes
Vocabulary Cards: Composing Shapes
Worksheet
Vocabulary Cards: Composing Shapes
Use these vocabulary cards with the EL Support Lesson: Composing Shapes.
1st grade
Math
Worksheet
Constructing Geometric Shapes
Constructing Geometric Shapes
Worksheet
Constructing Geometric Shapes
Give students practice composing and constructing geometric shapes with this seventh-grade geometry worksheet!
7th grade
Math
Worksheet
Hexuzzle 2
Hexuzzle 2
Game
Hexuzzle 2
Develop a deeper understanding of how shapes fit together to form a hexagon.
1st grade
Math
Game
Identifying Shapes By Attributes
Identifying Shapes By Attributes
Game
Identifying Shapes By Attributes
Kids practice identifying simple shapes based on descriptions of their attributes.
1st grade
Math
Game
Everyday Triangles
Everyday Triangles
Worksheet
Everyday Triangles
Children will take note of the everyday shapes that surround them in this fun geometry activity.
1st grade
Math
Worksheet
Winter Olympics Activity Book
Winter Olympics Activity Book
Workbook
Winter Olympics Activity Book
Kids can pay tribute to the athleticism and international diversity of winter sports with these paper crafts and art activities.
Math
Workbook

Search Triangle Educational Resources

Triangles are one of the basic shapes used in geometry and a fundamental concept in trigonometry. They are defined as polygons with three edges and three angles. Students as young as preschool can be introduced to triangles, but keeping track of the different types can be difficult. For more definitions and equations before starting on the resources, see the bottom of the page.

Learn More About Triangles

A triangle is a polygon that contains three edges and three angles, with the three angles always adding up to 180 degrees. Changing the lengths of the edges or the degrees of the angles can make a completely different triangle!

Types of triangles
There are three special types of triangles that are determined by looking at how many sides or angles are equal.
  • Equilateral Triangle: This shape has three equal sides and three equal angles that are all 60 degrees
  • Isosceles Triangle: For this triangle, only two of the sides are equal. Similarly, only two of the angles are equal (e.g. two angles are 40 degrees, while the third is 100 degrees).
  • Scalene Triangle: This last triangle has no equal sides and no equal angles.
Types of angles
You can also the types of angles to identify a triangle:
  • Acute Triangle: All three angles are less than 90 degrees (e.g. 70 + 60 + 50 = 180 degrees)
  • Right Triangle: One of the angles is exactly 90 degrees (e.g. 90 + 60 + 30 = 180 degrees)
  • Obtuse Triangle: One of the angles is greater than 90 degrees (e.g. 110 + 40 + 30 = 180 degrees)
Common Equations
Using some basic geometric formulas, you can easily calculate the area and perimeter of a triangle.
  • Area: The area of a triangle can be found by taking half of the base and multiplying it by the height of the triangle (Area = ½ x base x height). If you need a refresher in multiplication, check out our multiplications page.
  • Perimeter: The perimeter of the triangle is the distance around the edge of the triangle. In order to get the perimeter, you add up the lengths of all three sides.
Now that you have a basic understanding of triangles, check out the resources on this page or move over to the geometry page to see how other shapes are used in math.