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).
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...
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
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
Area of Circles and Probability
Learners investigate the area of squares and circles. In this geometry lesson plan, students calculate the area and probability of simple events. They work on a laptop using Safari.
Mathematics Assessment Project
Calculating Arcs and Areas of Sectors of Circles
Going around in circles trying to find a resource on sectors of circles? Here is an activity where pupils first complete an assessment task to determine the areas and perimeters of sectors of circles. They then participate in an...
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...
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...
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
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...
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...
Curated OER
Area and Circumference of Circles
Eighth graders find the area and circumference of circles. For this area and circumference of circles lesson plan, 8th graders follow a step by step lesson and then demonstrate the skills on their own with circles they are given.
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...
Willow Tree
Perimeter of Common Geometric Figures
Help learners understand that perimeter and circumference are one in the same. Learners apply their skills to determine the perimeter/circumference of triangles, rectangles, and circles. They then use the same strategy to find the...
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...
EngageNY
More Problems on Area and Circumference
Perimeter check! Pairs work on finding the areas of semicircles and quarter circles using a relationship with squares. The problems challenge pupils to find areas of composite figures made from rectangles, semicircles, and quarter circles. 
Curated OER
The Circle's Measure
Listen to the story "Sir Cumference and the Dragon of Pi" and solve the riddle and to save Sir Cumference from the knights.  Your students will love mixing an activity with story and will practice their measuring skills while...
Curated OER
The Geometry of Circles
Learners review the parts of a circle, calculate the circumference and area of a circle, and create student-made tests on the geometry of circles using educational software.
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...
Virginia Department of Education 
Going the Distance
Estimate the value of one of the most famous irrational numbers. The hands-on instructional activity instructs classmates to measure the circumference and diameters of circles using yarn. The ratio of these quantities defines pi.
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...
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. 
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...
Curated OER
Looking at Circumference
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.