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Lesson Plan
Curated OER

Study Buddies: Classifying Triangles

For Teachers 4th - 5th
In this math worksheet, students analyze an informative chart about the measurement and angles of equilateral, isosceles and scalene triangles. Students then answer 5 questions about classifying triangles.
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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 Triangle,...
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Lesson Plan
Digging Into Math

Classifying Triangles

For Teachers 4th - 8th Standards
Young mathematicians explore the world of three-sided shapes in this lesson on the different types of triangles. Starting with a general introduction to classification using Venn diagrams, children learn how to categorize triangles based...
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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.
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Lesson Plan
Curated OER

SuperShapes, Part 1; "Tri"ing Triangles

For Teachers 5th - 6th
An outstanding lesson on triangles awaits your math scholars. Learners focus on the triangle, which is the strongest of all polygons. They see the role that triangles play in the design of buildings, and learn about triangle...
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Lesson Plan
Curated OER

Acute Triangles

For Teachers 4th - 8th
Learners study acute triangles. They measure angles using a protractor, then classify the triangles as either right, obtuse, or acute. Everyone creates a design for a Navajo rug using only acute triangles.
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Lesson Plan
Curated OER

Exploring Polygons and The Greedy Triangle

For Teachers 1st - 3rd
Excellent lesson! Anne Linehane's geometry story, The Greedy Triangle, offers an opportunity to practice forming various types of polygons with your learners. Using elastic bands (or Chinese jump ropes), partners form the various shapes...
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Lesson Plan
Curated OER

What are the Kinds of Triangles?

For Teachers 5th
Fifth graders classify triangles. In this triangle lesson, 5th graders learn about the characteristics that make up a triangle. They are instructed through video, PowerPoint slides, and teacher-led demonstrations.
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Lesson Plan
Curated OER

Triangle Inequality Theorems Investigation

For Teachers 9th - 10th
Students estimate and measure triangles. In this geometry lesson, students identify the relationship between three sides and a triangle. They use the inequality theorem to decide if a triangle will be formed or not.
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Lesson Plan
Curated OER

Geometry Journal: Isosceles Triangles

For Teachers 10th - 12th
In this isosceles triangles worksheet, students justify and determine the symmetry of an isosceles triangle. They explore the bisector of rectangles. This three-page worksheet contains two problems. Answers are listed on page three.
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Lesson Plan
Curated OER

Right Triangles

For Teachers 4th - 8th
Learners classify triangles and make connections regarding angle measurements and attributes of acute, right, and obtuse triangles. They listen to teacher define and explain triangles. Everyone imagines a place where a broken wing for a...
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Lesson Plan
Curated OER

Branding Circles, Squares, Rectangles, Triangles

For Teachers K
Compare and classify 2-D shapes! Kindergarteners inspect the attributes of plane shapes and examine shapes in everyday life. They label the circles, squares, rectangles, and triangles they find. This is the website where you can find the...
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Lesson Plan
Curated OER

Geometry and Quilting

For Teachers 4th - 5th
Students create a quilt square for a class quilt using at least three, two-dimensional geometric figures. They research and write a brief description of at least two different quilt patterns that they find. Pupils discuss that quilts are...
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Lesson Plan
Curated OER

The Truth About Triangles And Proofs

For Teachers 9th - 12th
Learners engage in a lesson that is about the classification of triangles and the mathematical proofs involved in working with them. They work on a variety of problems that are created by the teacher with the focus upon the importance of...
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Lesson Plan
Curated OER

Angles, Triangles, Quadrilaterals, Circles and Related

For Teachers 6th - 8th
Students classify angles. In this angles lesson, students explore the characteristics of angles, triangles, quadrilaterals and circles. They identify polygons and sing a classifying angles song. Students participate in a manipulative...
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Lesson Plan
Curated OER

2-D polygons

For Teachers 3rd - 6th
A hands-on activity uses the Zome modeling system, and helps young geometers either learn or review their knowledge of polygons. Students build as many different 2-dimensional polygons as possible: triangle, square, rectangle, pentagon,...
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Lesson Plan
Curated OER

Types of Triangles

For Teachers 1st - 2nd
Students classify triangles by the length of their sides. In this geometry lesson, students use a white board to demonstrate the angles of various triangles. Students construct an equilateral, isosceles, and a scalene triangle.
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Lesson Plan
Curated OER

How many isosceles Triangles Can You Find?

For Teachers 5th
Fifth graders solve problems while examining a variety of isosceles triangles.  In this isosceles triangle lesson, 5th graders examine shapes to find their characteristics.  Students pay particular attention to the characteristics of...
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Lesson Plan
Curated OER

Isosceles Triangles

For Teachers K - 2nd
Students investigate triangles. In this shapes geometry lesson, students define and state the attributes for equilateral, scalene, and isosceles triangles. Students locate the prefix "tri" in a variety of words and make connections with...
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Lesson Plan
Curated OER

Classifying Geometric Figures

For Teachers 4th
Fourth graders recognize and classify geometric figures. For this geometry lesson, 4th graders read the books Shape Up and The Greedy Triangle and prepare a short report on the shapes mentioned in the text. Students compare the polygons...
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Lesson Plan
Curated OER

Varieties of Quadrilaterals

For Teachers 4th - 7th
Learners classify quadrilaterals, In this quadrilaterals lesson, students watch a video about parallelograms, discuss the different types of quadrilaterals, and complete a worksheet classifying quadrilaterals.
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Lesson Plan
Curated OER

Exploring Geometric Figures

For Teachers 10th
Tenth graders explore mathematics by participating in hands-on daily activities. Learners identify a list of different shapes and classify them by shape, size, sides and vertices. They utilize tangrams and geometric pieces to gain an...
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Lesson Plan
Curated OER

Geometric Shapes

For Teachers 5th - 7th
Students identify polygons.  For this geometric shape lesson, students explore the characteristics of polygons.  They identify polygons, and classify triangles according to their sides and angles.  Students create a poster representing...
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Lesson Plan
Curated OER

Triangle Inequality Theorem

For Teachers 8th - 10th
Students use the inequality theorem to solve triangles and their properties. In this geometry lesson, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length needed to make a...