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Lesson Plan
Mathematics Assessment Project

Inscribing and Circumscribing Right Triangles

For Teachers 9th - 12th Standards
High schoolers attempt an assessment task requiring them to find the radii of inscribed and circumscribed circles of a right triangle with given dimensions. They then evaluate provided sample responses to consider how to improve their...
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Assessment
Concord Consortium

Circumscribed Polygon

For Students 11th - 12th Standards
Trigonometry teachers often go off on a tangent, and here's a activity that proves it! First, young mathematicians use a formula with tangent to prove a formula correct for area. Then, they draw conclusions about the area of a circle...
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Assessment
Inside Mathematics

Circles in Triangles

For Teachers 9th - 12th Standards
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
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Unit Plan
Mathematics Vision Project

Circles: A Geometric Perspective

For Teachers 10th - 12th Standards
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
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Assessment
Mathematics Assessment Project

Circles and Squares

For Students 9th - 12th Standards
Squares, and circles ... and squares, and more circles. In this high school assessment task, pupils investigate the ratio of areas of two squares that are circumscribed and inscribed in a circle. They then determine the ratio of the area...
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Unit Plan
Mathematics Vision Project

Module 5: Circles A Geometric Perspective

For Teachers 9th - 12th Standards
Circles, circles, everywhere! Pupils learn all about circles, central angles, inscribed angles, circle theorems, arc length, area of sectors, and radian measure using a set of 12 lessons. They then discover volume formulas through...
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Lesson Plan
Curated OER

Circumscribing a Circle About a Triangle

For Teachers 9th - 12th Standards
Pupils circumscribe a circle about a triangle. They construct a triangle using Cabri Jr and then circumscribe it. They then use knowledge of perpendicular bisectors and circumcenters to locate the center of the circle and then...
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Worksheet
Curated OER

Circles

For Students 10th
In this circles activity, 10th graders solve and complete 20 different problems related to various circles. First, they find the radius and diameter of a circle with a given circumference. Then, students determine the measure of each...
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Worksheet
Curated OER

Circles and Squares

For Students 9th - 12th
In this area worksheet, students find the ratio of 1 area problem.  Students find the ratio of areas of inscribed circles to circumscribed squares.
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Lesson Plan
EngageNY

Construct a Nine-Point Circle

For Students 9th - 10th Standards
There are an infinite number of points on a circle; can you find nine of them? After putting together a nine-point circle, pupils use constructions and their knowledge of triangle segments to determine the center of the circle. Learners...
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Performance
Radford University

Building a Recreation Center

For Teachers 9th - 12th Standards
It's all about location, location, location. Small groups work to find the best spot for a rec center to serve three different communities. Learners construct the inscribed and circumscribed circles of a triangle to find the best place....
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Lesson Plan
Curated OER

Circumscribed Polygons

For Teachers 9th - 10th
Students investigate polygons and construct ferris wheels. In this geometry lesson plan, students create a circle and differentiate properties of circles and polygons. They compare the relationship between angles and circumscribed polygons.
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Lesson Plan
Curated OER

Area Of A Circle

For Teachers 5th
Fifth graders experience a lesson to investigate the methods for finding the area of a circle. They use the drawing of segments in order to visualize how a circle can be proposed of many parts. Then students brainstorm in order to derive...
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Lesson Plan
EngageNY

Law of Sines

For Teachers 11th - 12th Standards
Prove the Law of Sines two ways. The ninth segment in a series of 16 introduces the Law of Sines to help the class find lengths of sides in oblique triangles. Pupils develop a proof of the Law of Sines by drawing an altitude and a second...
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Lesson Plan
Curated OER

Special Triangles and Circles

For Teachers 9th - 11th
Students investigate special triangles and circles. In this geometry instructional activity, students construct a perpendicular bisector and discuss angles of a triangle. They find the angle bisectors, vetex and the types of circle...
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Assessment
EngageNY

Geometry Module 5: Mid-Module Assessment

For Teachers 9th - 12th Standards
How can you formally assess understanding of circle concepts? Pupils take a mid-module assessment containing five questions, each with multiple parts.
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Assessment
1
1
Balanced Assessment

Dart Boards

For Students 11th - 12th Standards
Bulls eye! Design dart boards with specific chances of winning. Individuals determine the probability of hitting a circular and a triangular dart board inscribed in squares. They create dart boards that have a 50 percent chance of...
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Lesson Plan
EngageNY

Proving the Area of a Disk

For Teachers 9th - 10th Standards
Using a similar process from the first lesson in the series of finding area approximations, a measurement resource develops the proof of the area of a circle. The problem set contains a derivation of the proof of the circumference formula. 
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Lesson Plan
Curated OER

THE AREA OF A CIRCLE

For Teachers 7th - 12th
Pupils examine the relationship between circumference and diameter and how to use the formula to find the area of a circle.  In this circle lesson students divide into groups and complete an activity. 
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Activity
1
1
Curated OER

Task: Grain Storage

For Teachers 7th - 10th Standards
Farming is full of mathematics, and it provides numerous real-world examples for young mathematicians to study. Here, we look at a cylinder-shaped storage silo that has one flat side. Given certain dimensions, students need to determine...
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Worksheet
Curated OER

Lesson 5.3 Vocabulary Quiz: Concurrent Lines, Medians, & Altitudes

For Students 10th - 12th
In this vocabulary worksheet, students match a given vocabulary word to the correct definition.  Words include such terms as altitude, centroid, circumcenter, circumscribed circle, inscribed circle, median and orthocenter.  This one-page...
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Lesson Plan
Curated OER

History and the Approximations of pi

For Teachers 7th - 8th
Middle schoolers investigate Pi. For this mathematics lesson, learners discuss the history of Pi and determine how the approximation of Pi was discovered.
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Lesson Plan
Curated OER

Connecting Area Formulas Produces a Beautiful Formula

For Teachers 11th - Higher Ed
In this math worksheet, students find the area of the triangle using the formula of 1/2 bh. Then they find the area using an alternative method.
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Lesson Plan
Curated OER

Modeling Permutation Group

For Teachers 9th - 11th
Students explore the concept of transformations. In this transformations lesson, students construct an equilateral triangle and a square with a circumscribed circle. Students reflect and rotate their constructions.