Lesson Plan
Curated OER

The Pythagorean Theorem and Classifying Triangles

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

Toothpick Triangles

For Teachers 4th - 8th
Students draw a chart (included in the lesson) to use with their investigation. They review terminology of triangles and receive toothpicks to use in the lesson. Beginning with three toothpicks, students form a triangle. They complete...
Lesson Plan
Illustrative Mathematics

Are These Right?

For Teachers 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

Exploring Polygons and The Greedy Triangle

For Teachers 1st - 3rd
Excellent activity! 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

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.
Lesson Plan
Curated OER

Identifying Angles

For Teachers 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

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...
Lesson Plan
Curated OER

Triangle Inequality Theorem

For Teachers 8th - 10th
Learners 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 length...
Lesson Plan
Curated OER

Obtuse Triangles

For Teachers 4th
Fourth graders explore obtuse triangles. In this geometry instructional activity, 4th graders make obtuse triangles with paper and scissors. They determine how to find the center of their triangle.
Lesson Plan
Curated OER

Review of Triangles

For Teachers 8th - 10th
Learners investigate the Pythagorean Theorem. In this geometry instructional activity, 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

Triangles Introduction

For Teachers K - 3rd
Students explore geometry by drawing various shapes in class. In this triangle characteristics lesson, students identify the attributes that classify a shape as a triangle and practice using their bodies to create triangles in class....
Lesson Plan
Curated OER

Interior and Exterior Angles of Polygons

For Teachers 9th - 10th
Young scholars identify interior and exterior angles of polygons. In this geometry lesson, students add interior and exterior angles of polygons. They use angle theorems to solve the problems.
Lesson Plan
Curated OER

Triangle Classification

For Teachers 9th - 12th
Students classify different types of triangles. In this geometry instructional activity, students identify and use properties of triangles. They differentiate between isosceles and equilateral triangles.
Lesson Plan
Curated OER

Angles in Triangles

For Teachers 8th
Eighth graders translate word problems using mathematical ideas. In this geometry lesson, 8th graders identify angles of triangles using equations and the triangle sum theorem. They create angles with a protractor and straight edge.
Lesson Plan
Curated OER

Geometry and Measurement

For Teachers 6th - 8th
Students view a right triangle displayed by the teacher. Students measure legs and the interior angles of the triangle. They look for a pattern or relationship between the legs and angles. Students use pegboards and string to create more...
Lesson Plan
Beacon Learning Center

The Fun Polygon

For Teachers 4th - 6th Standards
Junior geometers use hands-on manipulatives to explore and describe the properties and attributes of a fundamental polygon, the triangle. They learn different kinds of angles and their measurements. This well-written lesson plan provides...
Lesson Plan
Curated OER

Fractals

For Teachers 10th - Higher Ed
Students explore the concept of fractals. In this fractal lesson, students use applets to explore Koch's Snowflake, Sierpinski's Triangle, and other fractals. Students develop these concepts through exploration and teacher guided...
Lesson Plan
Curated OER

Pythagorean Relationships

For Teachers 9th - 12th Standards
Oh that Pythagorean Theorem is so useful. Learners engage in a 45 minute learning activity that requires them to solve for missing angles and sides of a right triangle. They'll use the Pythagorean Theorem to find the rations of sides and...
Lesson Plan
Curated OER

Quadrilateral Attributes

For Teachers 7th - 8th
Students classify quadrilaterals. In this quadrilateral lesson, students identify the characteristics of quadrilaterals. They write their findings in a journal. Students use geoboards to create quadrilaterals from given descriptions.
Lesson Plan
Curated OER

CSI Investigation of Congruence and Similarity

For Teachers 9th - 12th
Pupils differentiate between similarity and congruence using polygons. In this geometry lesson, students label triangles based on their properties. They find missing sides and angles using the interior sum theorem.
Lesson Plan
Curated OER

The Search for Pythagoras' Treasure

For Teachers 8th - 10th
Students identify and define properties of triangles. In this geometry lesson plan, students identify the missing sides and angles of right triangles. They use the rules of the Pythagorean Theorem to solve their problems.
Lesson Plan
Curated OER

Surface Area with Polydrons

For Teachers 3rd - 4th
Students explore measurements by analyzing geometric shapes. In this surface area instructional activity, students identify the terms volume, weight, perimeter and area in order to find the requested measurements of specific polygons....
Lesson Plan
Curated OER

Pythagorean Theorem by Graphic Manipulation

For Teachers 7th - 9th
There are many different ways to show a proof of the Pythagorean Theorem.  Here is a nice hands-on paper cutting activity that shows a graphic representation. You can even challenge your young Pythagoreans to come up with their own...
Lesson Plan
Curated OER

Powerful Polygons

For Teachers 2nd - 4th
Students scan the classroom to find different common shapes. They listen as the teacher defines polygon and regular polygon. The teacher demonstrates regular polygons via the Internet and the "Math is Fun" web site. Students go outside...