Curated OER
The Circumference of a Circle and the Area of the Region it Encloses
Bring your math class around with this task. Learners simply identify parts of a given circle, compute its radius, and estimate the circumference and area. It is a strong scaffolding exercise in preparation for applying the formulas for...
Curated OER
Measuring the Area of a Circle
When mathematical errors happen, part of the learning is to figure out how it affects the rest of your calculations. The activity has your mathematicians solving for the area of a circular pipe and taking into consideration any errors...
Curated OER
Area and Circumference of Circles
Young scholars calculate the area and circumference of a circle as the lesson is presented through an animated Microsoft PowerPoint presentation. They then complete a project to review the previous day's material.
Curated OER
The Area of a Circle
Eighth graders find the circumference and diameter of several lids, show the relationship of the two measurements and derive the formula for finding the area of a circle. In this area of a circle lesson plan, 8th graders find...
EngageNY
Proving the Area of a Disk
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...
Illuminations
Circumference and Areas of Circles
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 instructional activity, pupils understand how to find the radius,...
Curated OER
Super Shapes Part 2 - Circles
Through the use of Internet, video, and hands-on activities, youngsters learn the parts and characteristics of a circle. This fantastic lesson has some excellent website activities included in the plan. Your kids will have a much greater...
Virginia Department of Education 
Arc Length and Area of a Sector
What do skateboarding and baked goods have in common with math? You can use them to connect half-pipe ramps and cakes to arcs and sectors. Pupils compare the lengths of three different ramp options of a skate park. They calculate the...
EngageNY
The Most Famous Ratio of All
Pupils develop a definition of a circle based upon its radius in the 17th segment of a 28-part series. They determine the relationship between the radius and the diameter of a circle. To round out the lesson, they use the formula for the...
Curated OER
Equation of a Circle
Learners write the equation of a circle. In this geometry lesson, students check the solution of a coordinate pair by evaluating them. They graph the circle given the equation and radius.
Curated OER
Area and Circumference of Circles
Learners view two PowerPoints and practice computing the area and circumference of circles. They must use given formulas to make their computations. The lesson includes links to both PowerPoints as well as a worksheet (with answer key).
EngageNY
Decimal Expansion of Pi
Develop a better understanding of the value of pi. Learners explore the area of a circle using estimation and graph paper. While continuing to estimate the area of the circle using smaller and smaller grids, the number pi emerges. 
EduGAINs
Discovery of Pi
Serve up a slice of math for Pi Day! A combination of fun, hands-on lessons and helpful worksheets encourage learners to practice finding the radius, diameter, and circumference of different circles.
Illustrative Mathematics
Stained Glass
A complex question looking for the total cost of a stained glass window by calculating area and circumference of a circle. With detailed components, this activity will challenge your designers to figure out if they have enough money to...
Curated OER
Around the Clock
Middle schoolers discover the relationship between the circumference of a circle and its diameter. They find the length of an arc of a circle.Students use estimation strategies in real-world applications to predict results (i.e.,...
National Wildlife Federation
What is DBH?
When measuring the circumference of a tree, does it matter how high you place the measuring tape? Most scholars have never considered this question, but scientists know that measurement techniques must be standardized. The 13th lesson in...
Illustrative Mathematics
Eratosthenes and the Circumference of the Earth
The class gets to practice being a mathematician in ancient Greece, performing geometric application problems in the way of Eratosthenes. After following the steps of the great mathematicians, they then compare the (surprisingly...
Virginia Department of Education 
Surface Area and Volume of a Cylinder
Surface area or volume? Pupils first review the difference between surface area and volume. They then use a two-dimensional net that helps them develop formulas for the surface area and volume of cylinders.
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
Exploring Circles
Students explore circles using a graphing calculator. In this circles lesson, students write the equation of a circle with a given center and radius length. Students find the most appropriate model for each combination of data they...
Illustrative Mathematics
Seven Circles III
A basic set-up leads to a surprisingly complex analysis in this variation on the question of surrounding a central circle with a ring of touching circles. Useful for putting trigonometric functions in a physical context, as well as...
Curated OER
Circles Minilab
Students learn how to measure the diameter and circumference of a circle. In this circle lesson, students organize their data to create a graph. Students utilize their graph to make an inference about the slope of pi.
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
A Slice of Pi
Math pupils, by viewing a video, discover the history of pi and some of the applications of its uses in the world today. They conduct an experiment by measuring the diameter and circumference of various circular objects to calculate...