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 instructional activity, 5th graders examine shapes to find their characteristics.  Students pay particular attention to...
Handout
McGraw Hill

Triangles

For Students 4th - 7th Standards
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...
Lesson Plan
Curated OER

Isosceles Triangles

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

Geometric Figures-Triangles

For Teachers 4th
Fourth graders explore triangles. In this math lesson, 4th graders discuss the different types of triangles. Students create triangles using wiki sticks. Students complete an online matching game.
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...
Lesson Plan
Curated OER

Isosceles Triangle Investigation

For Teachers 9th - 12th
Students solve problems with isosceles triangles. For this geometry lesson, students identify and use the properties of triangles to solve their problems. They find the median, altitude, and angles to the triangles.
Lesson Plan
Curated OER

Triangles

For Teachers 6th - 10th
Students 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...
Worksheet
Raytheon

Understanding Triangles

For Students 6th - 8th
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...
Lesson Plan
Curated OER

Exploring Centers of a Triangle: Part 2

For Teachers 10th - 12th
Students model and solve a real-world problem by constructing the centroid of a triangle. They explore relationships of the medians of a triangle and investigate how the centroid partitions each of the medians. Students investigate...
Lesson Plan
Curated OER

Angles, Triangles, Quadrilaterals, Circles and Related

For Teachers 6th - 8th
Students classify angles. For 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

Special Right Triangles

For Teachers 9th - 10th
Students identify different types of special right triangles. In this geometry lesson, students differentiate between right triangles and isosceles triangles. they construct the triangles using geometry software and make conjectures...
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...
Lesson Plan
Curated OER

Triangle Inequality Theorem

For Teachers 8th - 10th
Young scholars use the inequality theorem to solve triangles and their properties. In this geometry instructional activity, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary...
Lesson Plan
Arizona State University

Tricorn Triangles

For Teachers K - 1st Standards
Help your learners examine triangles. Pupils explore the different sizes and measurements of triangles. They discover triangles can be isosceles or scalene, and examine the attributes of triangles. Here is the website where you can...
Lesson Plan
Curated OER

Review of Triangles

For Teachers 8th - 10th
Students investigate the Pythagorean Theorem. For this geometry lesson, students define angles and sides of right triangles. They calculate the area and surface area using formulas derived by the Pythagorean Theorem.
Lesson Plan
Curated OER

Triangle Side Lengths and Angles Measures

For Teachers 9th - 10th
Students identify missing sides and angles. In this geometry lesson, students use triangular theorems to identify the missing sides. They use the Pythagorean Theorem to find the different ratios of each side.
Lesson Plan
Curated OER

Angle-Side Relationships

For Teachers 9th - 12th
Students calculate the different sides and angles of a triangle. In this geometry lesson, students use triangular properties to define the relationship between two triangle. They identify missing angles using the interior angle theorem.
Lesson Plan
Exploratorium

Rotating String Shapes

For Teachers 3rd - 5th
Here is a very interesting way of studying triangles and polygons. Pupils work together and use pieces of string to create a variety of shapes. Depending on how many kids are manipulating the string at any one time, the number of...
Lesson Plan
Curated OER

Trigonometry

For Teachers 8th
Eighth graders practice calculating the unknown length of a right angle triangle. They also examine the pythogoram theory in groups. They help each other work through the problems.
Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 7th - 10th
Students find the different ratios of a triangle. In this geometry instructional activity, students use the Pythagorean Theorem to solve for missing sides and angles on a right triangle. They use a robot to create a right triangle.
Handout
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Centre for Innovation in Mamatics Teaching

Area, Perimeter and Volume

For Students 5th - 8th Standards
Develop young mathematicians' knowledge of two- and three-dimensional shapes with this geometry workbook. From learning about the classifications of different shapes and figures to calculating their area, perimeter, and volume, this...
Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 9th - 11th
Students solve problems using the Pythagorean Theorem. In this geometry instructional activity, students identify the sides and angles of a right triangle. They find the different trigonometric ratios and solve using sine, cosine and...
Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 8th - 10th
Students investigate the properties and idea of the Pythagorean Theorem. In this algebra lesson, students identify the different parts of a right triangle and relate it to the Pythagorean Theorem. They do a robotic experiment to...
Lesson Plan
Curated OER

Octagon Lesson Plan

For Teachers 10th - 11th
Students investigate octagons using words and shapes. In this geometry lesson plan, students discuss the shape of an octagon using physical and symbolic models. They make conjecture about the shape and relate it to the real world.