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Worksheet
Curated OER

Find Radius of the Circles

For Students 5th - 6th
In this finding the radius of circles worksheet, students must calculate the radius of 4 circles. Students are given diameter and must write the radius on the line for each circle. 
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Worksheet
Curated OER

Find Radius/Diameter

For Students 2nd - 10th
In this geometry instructional activity, learners calculate the radius and the diameter of the five given circles. There is an answer key included.
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Lesson Plan
Illuminations

Circumference and Areas of Circles

For Teachers 7th - 12th Standards
Middle and high schoolers listen to a scenario about a puppy and use the scenario to develop formulas in order to find the area of a circle. In this circumference lesson, pupils understand how to find the radius, diameter, area of a...
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Lesson Plan
Curated OER

Discovering Pi/Welcome to Pi Day

For Teachers 9th - 12th
Students explore pi. In this circle measurement lesson plan, students define and identify radius, diameter, circumference, and perimeter. Students work in groups to measure several plastic lids and record their findings. Students compare...
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Lesson Plan
Curated OER

Circles-Diameter, Circumference, Radius and the Discovery of Pi

For Teachers 7th
Seventh graders measure the diameter, circumference and radius of a circle and find pi using the diameter and circumference. In this geometry lesson plan, 7th graders work in groups to find the diameter, radius, and circumference of...
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Worksheet
Curated OER

Finding the Sum of the Perimeters of 3 Small Circles

For Students 9th - 10th
In this geometry learning exercise, students find the sum of the perimeters of three small circles.  These small circles are tangent to each other and to a larger circle.  The centers of the small circles have their centers on the...
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Interactive
Curated OER

Circle Problems - Radius, Diameter, Circumference and Area

For Students 9th - 12th
In this online math worksheet, students determine the radius, circumference, diameter and area of circles. This excellent resource allows the students to check their answers, and to get "hints" should they run into difficulties. A...
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Lesson Plan
Curated OER

Finding the Circumference and Area of a Circle

For Teachers 6th
Sixth graders discover what circumference is.  In this measurement instructional activity, 6th graders identify the radius and diameter of different circles. Students discover how to find the area of a circle using the radius and diameter.
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Lesson Plan
EngageNY

Arcs and Chords

For Teachers 9th - 10th Standards
You've investigated relationships between chords, radii, and diameters—now it's time for arcs. Learners investigate relationships between arcs and chords. Learners then prove that congruent chords have congruent arcs, congruent arcs have...
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Lesson Plan
Curated OER

Don't Be a Square

For Teachers 4th - 6th
Young scholars analyze the relationship between radius and diameter.  Students read Sir Cumference and the First Round Table then take measurements of circular items from around the room.  Young scholars compute the radius, diameter and...
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Lesson Plan
Curated OER

Circle Circus

For Teachers 3rd
Third graders find the radius and diameter of a bubble. In this radius and diameter lesson, 3rd graders create bubbles on their desk and find the radius and diameter of the bubble. Students work in partners to define circle terms and...
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Worksheet
Curated OER

Circles

For Students 10th
In this circles worksheet, 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

For Students 10th
In this circles worksheet, 10th graders solve and complete 13 various types of problems. First, they solve each set of triangles for the given variable. Then, students name a radius, a diameter, a tangent, a secant, a point of tangency,...
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Worksheet
Curated OER

Tangent Lines

For Students 10th
In this tangent lines instructional activity, 10th graders solve and complete 13 various types of problems. First, they solve the right triangles for the variables shown. Then, students name a radius, a diameter, a tangent, a secant, a...
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Lesson Plan
Curated OER

Looking at Circumference

For Teachers 6th - 8th
Middle schoolers understand where the number for pi comes from. They understand and use the formula for circumference. Students measure the circles given out and the diameters of those circles and record the results on their worksheet.
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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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Worksheet
Curated OER

Circle Formulas

For Students 10th
Tenth graders apply various circle formulas to determine radii, diameter, circumference, area, arc length, and sector area. The two page instructional activity contains twenty-five problems. Answers are not provided. 
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Activity
Illustrative Mathematics

Coins in a Circular Pattern

For Teachers 9th - 11th Standards
What starts as a basic question of division and remainders quickly turns abstract in this question of related ratios and radii. The class works to surround a central coin with coins of the same and different values, then develops a...
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Lesson Plan
Curated OER

Finding The Circumference Given The Radius

For Teachers 6th - 7th
Students develop an understanding of pi and the relationship between the diameter, radius and circumference. After a lecture/demo, students use construction paper and a compass to solve problems using diameter, radius and circumference.
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Lesson Plan
Curated OER

Circumference, Diameter, Radius

For Teachers 6th
Sixth graders will determine the circumference, diameter, and radius of a circle. In this circle lesson plan, 6th graders will measure the appropriate amount to find these measurements on circles.
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Worksheet
Curated OER

Circles: Finding Circumference

For Students 9th - 12th
In this circles worksheet, high schoolers find the circumference of 20 circles.  Students find the circumference given the radius, diameter, and area of various circles.
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Lesson Plan
Curated OER

Geometry: Area, Scale Factor, Circumference

For Teachers 5th - 8th
In this geometry worksheet, students solve 10 problems regarding area, scale factors, and circumference. Students, in 3 of the problems, are given the circumference and asked to work backwards to find missing information.
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Lesson Plan
Curated OER

Discovering Pi

For Teachers 6th
Sixth graders measure circumference and diameter to the nearest eighth of an inch, record measurements on a spreadsheet, and use the internet to complete a "scavenger hunt" of facts concerning pi.
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Worksheet
Curated OER

Volume of Cylinders and Cones

For Students 7th - 8th
Line drawings of a circle, a cylinder, and a cone at the top of the page contain the formulae for area and volume of each shape. Learners complete the missing information in a chart that lists diameter, radius, height, and area and...