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Lesson Plan
Shodor Education Foundation

Triangle Area

For Teachers 6th - 9th Standards
While the lesson focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can they...
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Lesson Plan
EngageNY

Perimeter and Area of Triangles in the Cartesian Plane

For Students 9th - 12th Standards
Pupils figure out how to be resourceful when tasked with finding the area of a triangle knowing nothing but its endpoints. Beginning by exploring and decomposing a triangle, learners find the perimeter and area of a triangle. They then...
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Lesson Plan
Government of Hong Kong

Areas and Volumes - 2D Shapes

For Teachers 3rd - 6th Standards
Unfortunately for young mathematicians, the world isn't made entirely of parallelograms, triangles, and trapezoids. After first learning the area formulas for these common shapes, students apply this new knowledge to determine the area...
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Lesson Plan
Curated OER

Developing Formulas for Triangles and Quadrilaterals

For Teachers 10th
In this geometry worksheet, 10th graders determine the area of triangles, parallelograms, trapezoids, kites, and rhombuses. The one page worksheet contains eleven problems. Answers are included.
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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
Mathematics Assessment Project

Solving Problems with Circles and Triangles

For Teachers 9th - 12th Standards
After completing a task involving examining the ratio of areas of triangles and circles in a given figure, scholars examine sample responses to identify other strategies they could use to solve the problem.
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Lesson Plan
Curated OER

Investigation Area of Geometric Shapes

For Teachers 4th
Fourth graders use triangle paper to design patterns using geometric figures and find the areas of those figures by counting units. Students are assessed by determining which figure has the greatest area and explaining their reasoning.
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Lesson Plan
EngageNY

Using Trigonometry to Determine Area

For Students 9th - 10th Standards
What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...
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Lesson Plan
Curated OER

Triangles

For Teachers 3rd - 5th
This unit enables scholars to apply the rule for area of a triangle (area equals half base times height). They practice multiplication and division strategies as they calculate areas.
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Lesson Plan
Curated OER

Ratios for Area and Volume

For Teachers 5th - 8th
In this ratios for area and volume worksheet, students solve problems where they find the ratios for problems of shapes dealing with area and volume. Students complete 4 problems.
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Lesson Plan
Alabama Learning Exchange

Polygons-Changing Area Versus Changing Perimeter

For Teachers 5th - 8th Standards
Investigate the area and perimeter of polygons in this geometry lesson. Young geometers use grid paper to draw a quadrilateral and calculate its area and perimeter. They also read The Greedy Triangle to identify the changing shape of...
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Lesson Plan
Curated OER

Finding Areas of Triangles, Rectangles, and Circles

For Teachers 9th - 10th
Students find the areas of geometric shapes. In this geometry lesson students find and measure the sides, perimeters, and areas of quadrilaterals, triangles, and circles. Students relate the measures to the others by using formulas.
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Lesson Plan
Hotchalk

Triangle Sum Theorem

For Teachers 8th - 10th Standards
Your visual geometry learners will appreciate triangle drawings as they model the triangle sum theorem and algebraically solve to find the missing interior angle in a triangle. Practice problems increase in complexity and vary in their...
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Lesson Plan
Curated OER

Finding the Area of Shapes

For Teachers 3rd - 5th
In this area of shapes unit, upper graders participate in hands-on problem solving activities to find the formulas for the area of a parallelogram, a triangle, and a trapezoid. They manipulate the geoboard to explore relationships among...
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Lesson Plan
Curated OER

Area of Tangram Pieces

For Teachers 3rd - 4th
Mathematicians calculate the area of a tangram piece without using formulas. They use a geometry journal to record activities during this lesson. They make a set of tangrams and use them to compute area. They use what they discover to...
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Lesson Plan
Curated OER

Area Measures and Right Triangles

For Teachers 9th - 12th Standards
Your class will investigate the relationship among different triangles. This geometry lesson plan, demonstrates how to make a connection between triangles and the Pythagorean Theorem. They identify the missing side or angle of a triangle.
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Lesson Plan
EngageNY

Properties of Area

For Teachers 9th - 10th Standards
What properties does area possess? Solidify the area properties that pupils learned in previous years. Groups investigate the five properties using four problems, which then provide the basis for a class discussion.
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Lesson Plan
Willow Tree

Area of Common Geometric Figures

For Students 8th - 11th Standards
Scholars can use area formulas, but can they apply what they know about area? The lesson challenges learners to think logically while practicing finding area of shapes such as rectangles, circles, parallelograms, triangles, and other...
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Lesson Plan
EngageNY

Real-World Area Problems

For Students 7th Standards
Not all structures take the shape of a polygon. The 21st lesson in a series of 29 shows young mathematicians they can create polygons out of composite shapes. Once they deconstruct the structures, they find the area of the composite figure.
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Lesson Plan
EngageNY

The Scaling Principle for Area

For Teachers 9th - 10th Standards
As they investigate scaling figures and calculate the resulting areas, groups determine the area of similar figures. They continue to investigate the results when the vertical and horizontal scales are not equal. 
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Lesson Plan
Willow Tree

Surface Area of Three-Dimensional Figures

For Students 8th - 11th Standards
Lateral area and surface area are simple concepts, but calculating them is not as easy! Using formulas, learners calculate lateral area and surface area for the same three-dimensional figures. The resource discusses the formula variables...
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Lesson Plan
Virginia Department of Education

Area and Perimeter

For Students 8th Standards
Develop a strategy for finding the area and perimeter of irregular figures. Building on an understanding of finding area and perimeter of rectangles and triangles, learners apply the same concepts to composite figures. After practicing...
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Lesson Plan
Curated OER

Algebra/Geometry Institute Summer 2009 - Triangles and the Pythagorean Theorem

For Teachers 7th
Seventh graders find the perimeter and area of triangles.  In this finding the perimeter and area of triangles lesson, 7th graders find the perimeter and area of triangles given two sides.  Students find the missing side by using the...
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Lesson Plan
Curated OER

A Practical Application For Area

For Teachers 1st
First graders investigate the concept of surface area and find the coverage for the surfaces in a building that includes carpet or walls. The application of finding the area is practical using the everyday objects to help them to make...