Illustrative Mathematics
Are These Right?
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...
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The Pythagorean Theorem and Classifying Triangles
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).
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Toothpick Triangles
Learners 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...
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Exploring Polygons and The Greedy Triangle
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),...
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Triangle Inequality Theorems Investigation
Students estimate and measure triangles. In this geometry lesson plan, 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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Identifying Angles
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.
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Exploring Geometric Figures
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...
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Triangle Inequality Theorem
Students use the inequality theorem to solve triangles and their properties. For this geometry lesson, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length needed to make a...
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Obtuse Triangles
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.
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Review of Triangles
Students investigate the Pythagorean Theorem. In 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.
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Triangles Introduction
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....
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Interior and Exterior Angles of Polygons
Students 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.
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Triangle Classification
High schoolers classify different types of triangles. In this geometry lesson, students identify and use properties of triangles. They differentiate between isosceles and equilateral triangles.
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Geometry and Measurement
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...
Beacon Learning Center
The Fun Polygon
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...
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Fractals
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...
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Pythagorean Relationships
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...
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CSI Investigation of Congruence and Similarity
Students differentiate between similarity and congruence using polygons. In this geometry lesson plan, students label triangles based on their properties. They find missing sides and angles using the interior sum theorem.
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The Search for Pythagoras' Treasure
Students identify and define properties of triangles. In this geometry lesson, students identify the missing sides and angles of right triangles. They use the rules of the Pythagorean Theorem to solve their problems.
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Surface Area with Polydrons
Students explore measurements by analyzing geometric shapes. In this surface area activity, students identify the terms volume, weight, perimeter and area in order to find the requested measurements of specific polygons. Students utilize...
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Pythagorean Theorem by Graphic Manipulation
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...
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Powerful Polygons
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...
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An Introduction to Quadrilaterals
Learners explore different types of quadrilaterals. Students define the terminology used with quadrilaterals. They create particular quadrilaterals based on specific characteristics of the quadrilaterals using an online tool.
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Meet the Polygon Family
Fourth graders investigate regular polygons. In this regular polygon lesson, 4th graders explore the attributes of different polygons. Students work in groups to complete a KWL chart regarding polygons.