Lesson Plan
Curated OER

The Pythagorean Theorem and Classifying Triangles

9th - 12th Standards
Through the examination of the relationship between the lengths of the sides of a triangles students will learn the classification of triangles (acute, right, or obtuse).
Lesson Plan
Curated OER

Study Buddies: Classifying Triangles

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.
Lesson Plan
Alabama Learning Exchange

What You Know About the Bermuda Triangle?

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.
Lesson Plan
National Security Agency

Classifying Triangles

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...
Lesson Plan
Curated OER

Toothpick Triangles

4th - 8th
Students draw a chart (included in the instructional activity) to use with their investigation. They review terminology of triangles and receive toothpicks to use in the instructional activity. Beginning with three toothpicks, students...
Lesson Plan
Digging Into Math

Classifying Triangles

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

Acute Triangles

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.
Lesson Plan
Curated OER

SuperShapes, Part 1; "Tri"ing Triangles

5th - 6th
An outstanding instructional activity 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...
Lesson Plan
Illustrative Mathematics

Are These Right?

3rd - 5th Standards
Is that a right triangle or a wrong triangle? Young mathematicians look at eleven different shapes and use a measuring tool of their choice to determine which triangles have right angles. Consider cutting out sets of the shapes to...
Lesson Plan
Curated OER

Classifying Triangles Based On Properties of Angles

5th Standards
The interactive lesson featured here calls for the use of a Smartboard for sorting and classifying shapes. Then, pupils discuss the rules they followed for sorting their shapes, particularly focusing on the properties of angles. While...
Lesson Plan
Curated OER

Exploring Polygons and The Greedy Triangle

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),...
Lesson Plan
Curated OER

Exploring Geometric Figures

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...
Lesson Plan
Curated OER

Right Triangles

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...
Lesson Plan
Curated OER

Geometry Journal: Isosceles Triangles

10th - 12th
In this isosceles triangles worksheet, learners 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.
Lesson Plan
Curated OER

Types of Triangles

1st - 2nd
Young scholars classify triangles by the length of their sides. In this geometry instructional activity, students use a white board to demonstrate the angles of various triangles. Young scholars construct an equilateral, isosceles, and a...
Lesson Plan
Curated OER

The Greedy Triangle-Intro to Geometric Shapes

4th - 6th Standards
 In this geometry lesson, learners read The Greedy Triangle and use geoboards to construct geometric shapes. They identify the number of sides and angles each shape has.
Lesson Plan
Curated OER

Identifying Angles

4th - 5th
Students identify names of angles. They use a large clock to demonstrate angles using certain times of day. Given a geoboard, students create figures with acute, right, and obtuse angles.
Lesson Plan
Curated OER

Triangles

6th - 10th
Pupils identify triangles in the real world and construct their own triangle using drinking straws. They explore abstract triangles and find additional geometric shapes such as trapezoids. Students discuss similar shapes and examine the...
Lesson Plan
Curated OER

8th Grade Math Classifying Triangles and Quadrilaterals

8th
Eighth graders engage in a lesson that is about classifying polygons with the focus being upon specific triangles and quadrilaterals. They conduct activities using cutouts for kinesthetic learners to help make connections while...
Lesson Plan
Curated OER

Angles And Triangles

7th
Seventh graders participate in a lesson that is focused upon the concepts of classifying different angles and triangles. They practice classifying triangles according to its kind that includes types of angles, congruence, and vertices....
Lesson Plan
Curated OER

The Truth About Triangles And Proofs

9th - 12th
Students 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...
Lesson Plan
Curated OER

Angles, Triangles, Quadrilaterals, Circles and Related

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...
Lesson Plan
Curated OER

Isosceles Triangles

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...
Lesson Plan
Curated OER

Types of Triangles

5th
Fifth graders explore the required functions of the Geometer's Sketchpad. Using the computer software, they construct similar triangles and identify them by angles and sides. Students classify triangles. Afterward, they complete problems...