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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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Interactive
Scholastic

Study Jams! Area of a Triangle

For Students 4th - 6th Standards
Even though there is a wide variety of different triangles in the world, knowing a single equation allows us to find the area of each and every one of them. Follow along with this step-by-step presentation as Zoe clearly models how to...
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Worksheet
Curated OER

Area of Right-Angled Triangles

For Teachers 3rd - 5th Standards
There's a trick to solving the area of a triangle, and it involves a skill your geometers have already mastered. Help them discover the connection between finding a rectangle's area and finding a right triangle's area as they solve for...
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Lesson Plan
EngageNY

An Area Formula for Triangles

For Teachers 11th - 12th Standards
Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....
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Lesson Plan
Illustrative Mathematics

Finding Areas of Polygons, Variation 1

For Teachers 5th - 9th Standards
An exercise in finding the area of polygons by decomposing into triangles and composing into rectangles is the focus of this resource. Make several copies of the worksheet for each participant. Ask learners to use colored pencils to...
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Lesson Plan
2
2
Curated OER

Two Triangles' Area

For Teachers 7th - 9th Standards
Need an activity for teaching the Pythagorean Theorem? Geometry juniors apply the Pythagorean theorem to two triangles to determine a final calculation. 
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Lesson Plan
1
1
Curated OER

Areas of Geometric Shapes with the Same Perimeter

For Teachers 7th - 9th Standards
A triangle, square, hexagon, and circle all have a perimeter of one unit. Eighth graders must attempt to find the area of each and arrange them in order from least to greatest areas. A terrific task for applying four different area...
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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
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

Finding the Area of an Equilateral Triangle

For Teachers 9th - 11th Standards
The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...
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Lesson Plan
Curated OER

Perimeter and Area 5

For Teachers 6th - 8th
In this calculating area worksheet, students use their problem solving skills and the information provided to find the area of 6 triangles.
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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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Activity
Curated OER

Triangle Series

For Teachers 9th - 12th Standards
Your algebra learners emphasize the"geometric" in geometric series as they use a common ratio between algebraic terms and find that it corresponds to a repeated similarity transformation. 
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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
Illustrative Mathematics

Same Base and Height, Variation 2

For Teachers 5th - 7th Standards
This is a good model for learners to visualize triangles of the same base and height. They can can begin to comprehend that these triangles will have the same area no matter how the triangle is drawn. It is part of a series of resources...
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Lesson Plan
Illustrative Mathematics

Area of a Trapezoid

For Teachers 7th - 9th Standards
Here is a straightforward example of how to apply the Pythagorean Theorem to find an unknown side-length of a trapezoid. Commentary gives additional information on proving that the inside of the trapezoid is a rectangle, but is...
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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 activity challenges learners to think logically while practicing finding area of shapes such as rectangles, circles, parallelograms, triangles, and other...
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PPT
Curated OER

Who Wants to Be a Champion: Perimeter, Area, Symmetry

For Teachers 3rd - 5th
Have your learners practice finding the perimeter and area of geometric shapes using this resource. While just a simple review, this could be a wonderful way to solidify the concepts in their minds.
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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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Assessment
Mathed Up!

Area of Sector and Length of Arcs

For Students 9th - 12th Standards
Viewers learn how to apply proportional reasoning to find area of sectors and arc lengths with a video that starts off explaining how to find the areas of circle sectors and the lengths of arcs. Scholars then practice solving problems...
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Lesson Plan
Curated OER

Finding Area of Similar Figures

For Teachers 7th - 8th
Young scholars explore the concept of finding area of similar figures. In this finding area of similar figures lesson, students use pattern blocks to construct similar figures. Young scholars trace their construction and find the area....
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Interactive
Curated OER

Triangle Problems-Base, Height, and Area

For Students 10th
In this geometry worksheet, 10th graders find the base, height, or area of a triangle. The one page interactive worksheet contains ten questions. Answers and hints are included. 
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Workbook
1
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Centre for Innovation in Mamatics Teaching

Areas and Perimeters

For Students 3rd - 6th Standards
Cover some serious area in your geometry curriculum with this collection of worksheets. After first introducing the concept of area using the tiling method, this resource continues on to teach learners how to use the area and perimeter...
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Lesson Plan
EngageNY

Perimeter and Area of Polygonal Regions Defined by Systems of Inequalities

For Students 9th - 12th Standards
When algebra and geometry get together, good things happen! Given a system of inequalities that create a quadrilateral, learners graph and find vertices. They then use the vertices and Green's Theorem to find the area and perimeter of...