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Lesson Plan
EngageNY

Writing the Equation for a Circle

For Teachers 9th - 12th Standards
Circles aren't functions, so how is it possible to write the equation for a circle? Pupils first develop the equation of a circle through application of the Pythagorean Theorem. The lesson then provides an exercise set for learners to...
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Interactive
CK-12 Foundation

Restricted Domain and Range: Restricted Circle Radius and Area

For Students 9th - 12th Standards
There's no restriction to how much your class can learn about domain and range. Users of an interactive adjust the radius of a circle to see its effects on the area. They note how restrictions in the domain (radius) relate to...
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Worksheet
Raytheon

Geometry: Circles

For Students 6th - 8th
In this geometric circumference worksheet, 8th graders calculate the circumference of each of the 18 circles. The remaining pages of the worksheet include formulas and lesson ideas on finding the circumference of circles.
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Assessment
Concord Consortium

Three Circles

For Students 9th - 12th Standards
Round and round and round we go. Given a diagram of three circles, two of which share a point with the third circle, learners identify the radius of each circle. Doing so requires setting up and solving a system of equations based on the...
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Interactive
CK-12 Foundation

Circles Centered at the Origin: Dog

For Students 11th - Higher Ed Standards
How many bones can a dog on a leash reach? Class members move a dog on the end of its leash and determine whether it can reach bones located at specific points. The learners see whether the bone lies on the circle or outside of the...
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Worksheet
Curated OER

Circles: Geometry Review Worksheet

For Students 10th Standards
Tenth graders solve and complete 14 different geometry problems. First, they find the area and circumference of a circle with a given radius. Then, they find the area between a circle and an inscribed equilateral triangle given the...
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Lesson Plan
Curated OER

Area of Circles and Probability

For Teachers 8th - 12th
Students investigate the area of squares and circles. In this geometry lesson, students calculate the area and probability of simple events. They work on a laptop using Safari.
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Activity
Illustrative Mathematics

Tangent to a Circle From a Point

For Teachers 9th - 10th Standards
Learners see application of construction techniques in a short but sophisticated problem. Combining the properties of inscribed triangles with tangent lines and radii makes a nice bridge between units, a way of using information about...
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Lesson Plan
EngageNY

Recognizing Equations of Circles

For Teachers 9th - 12th Standards
What does completing the square have to do with circles? Math pupils use completing the square and other algebraic techniques to rewrite equations of circles in center-radius form. They then analyze equations of the form x^2 + y^2 + Ax +...
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Worksheet
Curated OER

Circles and Cylinders

For Students 10th
In this geometry lesson, 10th graders break down a circle and identify the different parts. They discuss chords, diameter, radius, circumference, major and minor segment. There are 42 problems broken down into 5 different sections.
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Lesson Plan
West Contra Costa Unified School District

Finding the Equation of a Circle

For Teachers 9th - 12th Standards
Tired of going around and around for a resource on circles? Scholars determine the general equation of a circle on a coordinate plane, then participate in an activity matching equations to the radii and centers of the circles they...
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Lesson Plan
Texas Instruments

Drawing a Line Tangent to a Circle

For Teachers 9th - 12th Standards
Explore lines tangent to a circle. In this math lesson, students manipulate circles and lines on a TI calculator. They draw a circle  and analyze perpendicular lines intersecting the circle in only one place. This activity works best if...
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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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Lesson Plan
Virginia Department of Education

Circles in the Coordinate Plane

For Teachers 9th - 11th Standards
Make the connection between the distance formula and the equation of a circle. The teacher presents a lesson on how to use the distance formula to derive the equation of the circle. Pupils transform circles on the coordinate plane and...
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Interactive
CK-12 Foundation

Equations of Circles: Finding the Equation of a Circle

For Students 11th - Higher Ed Standards
It's all about location and size. With the aid of the interactive, pupils explore the relationship between the location and size of a circle and its equation. The learners use that relationship to determine the equation of a circle given...
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Interactive
CK-12 Foundation

Circles Centered at the Origin: The Map of the Beta Solar System

For Students 11th - Higher Ed Standards
Calculate galactic orbits in a far-out resource. Pupils drag a point on a circle to graph the orbit of a fictional planet. Using the equation, they find points through which the orbit passes. To finish the simulation, users determine the...
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Interactive
CK-12 Foundation

Circles Not Centered at the Origin: Room Rearranging

For Students 11th - Higher Ed Standards
Where does a circular table fit best? Individuals move a circle representing a table into different quadrants of a room. Pupils determine which equation of the circle will place the table in the appropriate quadrant. A discussion...
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Worksheet
Curated OER

Circle Area, Perimeter and Circumference

For Students 7th - 9th
Use this geometry skills practice activity to have learners solve seven problems that require them calculate the circle area, perimeter, and circumference of circles.
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Worksheet
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K12 Reader

Anatomy of a Circle

For Students 4th - 5th Standards
Make sure your learners are well-versed in circles with a reading passage. Pupils will pick up some important circle-related terms as they read and respond to the five included questions.
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Worksheet
Curated OER

Quiz: Area of a Circle

For Students 7th - Higher Ed
Geometers test their mastery at finding the area of a circle with 10 basic problems. Circle diagrams show line segments, points, and diameter. Distance of radii are given. They use pi as 3.14 to calculate the area. No answer key is...
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Worksheet
Mt. San Antonio Collage

Circles

For Students 9th - 12th Standards
Don't circle around the topic, but get right to the center with tons of practice regarding circles in geometry. The note-incorporated worksheet provides guided practice through many topics such as central angles, inscribed polygons and...
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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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Worksheet
Curated OER

Circles

For Students 7th
In this circles worksheet, 7th graders identify and complete 6 different problems that include determining various parts of a circle. First, they identify and define each circle term listed on the left. Then, students color each term...
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Lesson Plan
EngageNY

Equations for Tangent Lines to Circles

For Teachers 9th - 12th Standards
Don't go off on a tangent while writing equations of tangent lines! Scholars determine the equations for tangent lines to circles. They attempt both concrete and abstract examples, such as a tangent line to the unit circle through (p, 0).