Noyce Foundation
Circular Reasoning
Examine the origin and application of pi in five different levels. The five lessons in the resource begin with an analysis of the relationship between the radius and circumference of a circle. The following lessons lead learners through...
EngageNY
Ferris Wheels—Tracking the Height of a Passenger Car
Watch your pupils go round and round as they explore periodic behavior. Learners graph the height of a Ferris wheel over time. They repeat the process with Ferris wheels of different diameters.
Curated OER
Geometry: Calculating the Area of a Circle
In this area worksheet, students use the perimeter or radius to determine the area of a circle. This one-page worksheet contains 8 problems. This worksheet may be produced in printed form. Answers may be viewed on-line.
Curated OER
Chords of a Circle
In this geometry worksheet, 10th graders calculate the length of a chord and the distance from the center of a circle or radius. They compare diameter, chords and radius. There are 10 questions with an answer key.
Curated OER
Area of a Circle Worksheet
In this geometry worksheet, 6th graders identify the area of the four given circles by using the given diameters. There is a space for students to show their work.
EngageNY
Rectangles Inscribed in Circles
Putting a rectangular object into a circular one—didn't the astronauts on Apollo 13 have to do something like this? Learners first construct the center of a circle using perpendiculars. They then discover how to inscribe a rectangle in a...
EngageNY
Geometry Module 5: End-of-Module Assessment
The lessons are complete. Learners take an end-of-module assessment in the last installment of a 23-part module. Questions contain multiple parts, each assessing different aspects of the module.
Mathematics Vision Project
Circles: A Geometric Perspective
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...
101 Questions
Penny Circle
Watch as your classes buy into a rich lesson full of information. A video opener challenges individuals to determine the number of pennies that fit in a circle with a 22-inch diameter. Using lesson materials, scholars collect data and...
Illustrative Mathematics
Tangent to a Circle From a Point
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...
Mathed Up!
Circle Theorems
Explore theorems involving circles. Individuals watch a video that reviews the basic parts of a circle. They learn about circle theorems and compete a worksheet of problems that use these theorems — putting their skills to work right away!
101 Questions
Coins in a Circle
Round and round you'll go! Learners watch as different-sized circles fill with coins. They collect data and then make a prediction about the number of coins that will fit in a large circular rug.
Illustrative Mathematics
Coins in a Circular Pattern
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...
Curated OER
Equivalent Expressions A.10
In this equivalent expressions worksheet, 9th graders solve and complete 9 different multiple choice problems. First, they determine the expression that is equivalent to the given equation. Then, students write the diameter of a number...
Inside Mathematics
Squares and Circles
It's all about lines when going around. Pupils graph the relationship between the length of a side of a square and its perimeter. Class members explain the origin in context of the side length and perimeter. They compare the graph to the...
Curated OER
Circumference and Area of Circles (B)
In this geometry worksheet, students calculate the area and circumference of 12 circles in which either the diameter or radius is shown. There are no formulas given on this page.
Curated OER
Parts of a Circle
Sixth graders use yarn, paper plate, and other materials to identify parts of a circle. In this parts of a circle lesson plan, 6th graders identify the circumference, radius, diameter, and other parts of a circle.
Curated OER
Parts of a Circle
In this geometric shapes instructional activity, students respond to questions that require them to identify chords, radii, diameters and centers of 4 circles.
EngageNY
Thales’ Theorem
Isn't paper pushing supposed to be boring? Learners attempt a paper-pushing puzzle to develop ideas about angles inscribed on a diameter of a circle. Learners then formalize Thales' theorem and use geometric properties to develop a proof...
EngageNY
Circles, Chords, Diameters, and Their Relationships
A diameter is the longest chord possible, but that's not the only relationship between chords and diameters! Young geometry pupils construct perpendicular bisectors of chords to develop a conjecture about the relationships between chords...
Curated OER
Pi Day: The Other Math Holiday!
Happy Pi Day! This collection of games, experiments, and activities leads participants through an exploration of the many aspects and attributes of that mysterious quantity, pi. Activities range from using statistical...
101 Questions
Suitcase Circle
Analyze patterns in a circular arrangement. After using a geometric construction to complete a circle, learners use proportional reasoning to make predictions. By determining the length of an arc built from suitcases, they estimate the...
CCSS Math Activities
Out of the Swimming Pool
Out of the swimming pool and into the math classroom! Young mathematicians analyze two linear functions representing the number of liters of water in a pool as it drains over time. They must evaluate functions, interpret function...
Curated OER
Algebra II - Lesson 10-3: Circles
In this equations of circles worksheet, students solve 4 short answer problems. Students find an equation of a circle given the center and radius.