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.
Curated OER
Circumferences, Diameters, and Radii
Young scholars explore circumferences, diameters, and radii. In this math lesson plan, students measure circumferences in inches and compute radii and diameters, given different circumferences.
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...
Curated OER
Inscribing a Hexagon in a Circle
This activity is a follow-on activity to inscribing a square in a circle. The overall problem is more complex. It deals with geometric constructions, properties of triangles, and regular hexagons. The final part of the activity...
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...
Curated OER
Discovering Pi/Welcome to Pi Day
Students explore pi. For this circle measurement lesson, students define and identify radius, diameter, circumference, and perimeter. Students work in groups to measure several plastic lids and record their findings. Students compare the...
Mathematics Assessment Project
Inscribing and Circumscribing Right Triangles
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...
Curated OER
Exploring Diameter and Circumference
Learn how to identify the diameter and circumference of a circle. Then, collect data on a circle and relate it to the diameter and circumference of a circle. Last, plot data and find the line of best fit.
Curated OER
Radius, Diameter and Area
Students identify the radius and diameter of a circle. In this geometry lesson, students calculate the volume and area of a cylinder and circle. They relate the circumference of a circle to Pi.
Curated OER
Circles and Pi
Students identify the relationship between the radius and Pi. For this geometry lesson, students calculate the circumference and area of a circle. They create visuals to help them see how the circumference relates to Pi.
Texas Instruments
Area of Circles
Students explore circles. In this algebra/geometry lesson, students discover the formula for the area of a circle, as they investigate the ratio of the area of a circle to the radius^2.
Curated OER
Discovering Pi
Define terminology related to a circle. Practice accuracy in measuring and then create a spreadsheet based on data collected from solving for parts of a circle. Groups can have fun analyzing their data as it relates to Pi.
Curated OER
Circles
Tenth graders explore and define the radius and diameter of a circle. In this geometry lesson plan, 10th graders calculate the circumference and area of a circle using real world objects and shapes. They discuss chords and lines...
Curated OER
Circles and Angles
Students identify tangents, chords and secants. In this geometry lesson, students graph circles and identify angles created by secant lines, tangent lines and chords.
Curated OER
Circle Relationships
Students explore circles. In this geometry lesson, students explore the relationship between the circumference of a circle, the distance a ball travels, and the number of rotations the ball must make in order to travel a certain...
Concord Consortium
Bicycle Chain
Model a bicycle chain with circles and tangent lines. Given the dimensions of the sprocket wheels, young scholars calculate the length of the chain that surrounds them. A second task has learners write a function for the length of a...
Curated OER
Consistent Circles
Students create a design of a circle. In this geometry lesson, students identify the measure of the diameter and radius of a circle. They graph and analyze their collected data and write equations based on direct variation.
Curated OER
Crop Circles
Students calculate the area and circumference of a circle. In this geometry lesson, students solve word problems with circles and create formulas to calculate the area. They find the rate and complex area of a circle.
Curated OER
Discovering Pi
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.
Curated OER
Diameter, Radius and Area
Students calculate the diameter, radius and area of a circle. In this geometry instructional activity, students investigate the different ratios of a circle. They calculate the surface are of each circle.
Curated OER
Power of a Point
Students solve problems by finding the radius or diameter. In this geometry instructional activity, students identify the tangent line of a circle and use properties of circles to find the radius. They relate circles to the real world.
Curated OER
Pi
Sixth graders read the book "Sir Cumference and Knights of the Round Table" to introduce them to the concept of Pi. As a class, they discover where Pi originated and define the terms circumference, radius and diameter. To end the...
Curated OER
3.14159265
Students discover the value of Pi. In this value of Pi lesson plan, students measure the circumference and diameter of various circles on their graphing calculator. Students find the ratio of the circumference to the diameter...
Mathematics Vision Project
Module 6: Trigonometric Functions
Create trigonometric functions from circles. The first lesson of the module begins by finding coordinates along a circular path created by a Ferris Wheel. As the lessons progress, pupils graph trigonometric functions and relate them to...